diff --git a/arch/arm/src/at32/at32_otgfshost.c b/arch/arm/src/at32/at32_otgfshost.c
index fdf7cb86482..a9e2119a2f7 100644
--- a/arch/arm/src/at32/at32_otgfshost.c
+++ b/arch/arm/src/at32/at32_otgfshost.c
@@ -1947,7 +1947,7 @@ static ssize_t at32_in_transfer(struct at32_usbhost_s *priv, int chidx,
                    * Small delays could require more resolution than is
                    * provided by the system timer.  For example, if the
                    * system timer resolution is 10MS, then
-                   * nxsig_usleep(1000) will actually request a delay 20MS
+                   * nxsched_usleep(1000) will actually request a delay 20MS
                    * (due to both quantization and rounding).
                    *
                    * REVISIT: So which is better?  To ignore tiny delays and
@@ -1957,7 +1957,7 @@ static ssize_t at32_in_transfer(struct at32_usbhost_s *priv, int chidx,
 
                   if (delay > CONFIG_USEC_PER_TICK)
                     {
-                      nxsig_usleep(delay - CONFIG_USEC_PER_TICK);
+                      nxsched_usleep(delay - CONFIG_USEC_PER_TICK);
                     }
                 }
             }
@@ -2262,7 +2262,7 @@ static ssize_t at32_out_transfer(struct at32_usbhost_s *priv,
            * transfer using the same buffer pointer and length.
            */
 
-          nxsig_usleep(5 * 1000);
+          nxsched_usleep(5 * 1000);
         }
       else
         {
@@ -3958,7 +3958,7 @@ static int at32_rh_enumerate(struct at32_usbhost_s *priv,
    * 100ms.
    */
 
-  nxsig_usleep(100 * 1000);
+  nxsched_usleep(100 * 1000);
 
   /* Reset the host port */
 
diff --git a/arch/arm/src/cxd56xx/cxd56_farapi.c b/arch/arm/src/cxd56xx/cxd56_farapi.c
index 4d174769cad..d0e09893998 100644
--- a/arch/arm/src/cxd56xx/cxd56_farapi.c
+++ b/arch/arm/src/cxd56xx/cxd56_farapi.c
@@ -205,7 +205,7 @@ void farapi_main(int id, void *arg, struct modulelist_s *mlist)
 
       /* NOTE: a workaround to finish rescheduling */
 
-      nxsig_usleep(10 * 1000);
+      nxsched_usleep(10 * 1000);
     }
 #endif
 
@@ -273,7 +273,7 @@ err:
 
       /* NOTE: a workaround to finish rescheduling */
 
-      nxsig_usleep(10 * 1000);
+      nxsched_usleep(10 * 1000);
     }
 #endif
 }
diff --git a/arch/arm/src/cxd56xx/cxd56_gnss.c b/arch/arm/src/cxd56xx/cxd56_gnss.c
index acbceda7093..78a4aa5024d 100644
--- a/arch/arm/src/cxd56xx/cxd56_gnss.c
+++ b/arch/arm/src/cxd56xx/cxd56_gnss.c
@@ -452,7 +452,7 @@ static int cxd56_gnss_start(struct file *filep, unsigned long arg)
     {
       /* GNSS requires stable RTC */
 
-      nxsig_usleep(100 * 1000);
+      nxsched_usleep(100 * 1000);
     }
 
   ret = cxd56_gnss_cpufifo_api(filep, CXD56_GNSS_GD_GNSS_START,
@@ -1453,7 +1453,7 @@ static int cxd56_gnss_start_test(struct file *filep, unsigned long arg)
         {
           /* GNSS requires stable RTC */
 
-          nxsig_usleep(100 * 1000);
+          nxsched_usleep(100 * 1000);
         }
 
       /* set parameter */
@@ -2768,7 +2768,7 @@ static int cxd56_gnss_open(struct file *filep)
     {
       /* GNSS requires stable RTC */
 
-      nxsig_usleep(100 * 1000);
+      nxsched_usleep(100 * 1000);
     }
 
   ret = nxmutex_lock(&priv->devlock);
diff --git a/arch/arm/src/cxd56xx/cxd56_nxaudio.c b/arch/arm/src/cxd56xx/cxd56_nxaudio.c
index 0e20e5d7fc9..c4e38fe539c 100644
--- a/arch/arm/src/cxd56xx/cxd56_nxaudio.c
+++ b/arch/arm/src/cxd56xx/cxd56_nxaudio.c
@@ -2957,7 +2957,7 @@ static int cxd56_start(struct audio_lowerhalf_s *lower)
 
           if (time < CXD56_MIC_BOOT_WAIT)
             {
-              nxsig_usleep((CXD56_MIC_BOOT_WAIT - time) * 1000);
+              nxsched_usleep((CXD56_MIC_BOOT_WAIT - time) * 1000);
             }
         }
     }
diff --git a/arch/arm/src/cxd56xx/cxd56_sdhci.c b/arch/arm/src/cxd56xx/cxd56_sdhci.c
index d2b47cbac00..264fb615c9b 100644
--- a/arch/arm/src/cxd56xx/cxd56_sdhci.c
+++ b/arch/arm/src/cxd56xx/cxd56_sdhci.c
@@ -3338,7 +3338,7 @@ void cxd56_sdhci_mediachange(struct sdio_dev_s *dev)
               break;
             }
 
-          nxsig_usleep(100000);
+          nxsched_usleep(100000);
           timeout -= 100000;
         }
     }
diff --git a/arch/arm/src/efm32/efm32_usbhost.c b/arch/arm/src/efm32/efm32_usbhost.c
index fa794055f29..ccafbcb3253 100644
--- a/arch/arm/src/efm32/efm32_usbhost.c
+++ b/arch/arm/src/efm32/efm32_usbhost.c
@@ -2276,7 +2276,7 @@ static ssize_t efm32_out_transfer(struct efm32_usbhost_s *priv,
            * transfer using the same buffer pointer and length.
            */
 
-          nxsig_usleep(20 * 1000);
+          nxsched_usleep(20 * 1000);
         }
       else
         {
@@ -3960,7 +3960,7 @@ static int efm32_rh_enumerate(struct efm32_usbhost_s *priv,
 
   /* USB 2.0 spec says at least 50ms delay before port reset. wait 100ms. */
 
-  nxsig_usleep(100 * 1000);
+  nxsched_usleep(100 * 1000);
 
   /* Reset the host port */
 
diff --git a/arch/arm/src/imx6/imx_enet.c b/arch/arm/src/imx6/imx_enet.c
index b9770702a71..dcf7ab0c75b 100644
--- a/arch/arm/src/imx6/imx_enet.c
+++ b/arch/arm/src/imx6/imx_enet.c
@@ -2043,7 +2043,7 @@ static inline int imx_initphy(struct imx_driver_s *priv, bool renogphy)
       retries = 0;
       do
         {
-          nxsig_usleep(LINK_WAITUS);
+          nxsched_usleep(LINK_WAITUS);
 
           ninfo("%s: Read PHYID1, retries=%d\n",
                 BOARD_PHY_NAME, retries + 1);
@@ -2216,7 +2216,7 @@ static inline int imx_initphy(struct imx_driver_s *priv, bool renogphy)
               break;
             }
 
-          nxsig_usleep(LINK_WAITUS);
+          nxsched_usleep(LINK_WAITUS);
         }
 
       if (phydata & MII_MSR_ANEGCOMPLETE)
diff --git a/arch/arm/src/imxrt/imxrt_ehci.c b/arch/arm/src/imxrt/imxrt_ehci.c
index 62c639ff087..22a1673253b 100644
--- a/arch/arm/src/imxrt/imxrt_ehci.c
+++ b/arch/arm/src/imxrt/imxrt_ehci.c
@@ -3811,7 +3811,7 @@ static int imxrt_rh_enumerate(struct usbhost_connection_s *conn,
    * reset for 50Msec, not wait 50Msec before resetting.
    */
 
-  nxsig_usleep(100 * 1000);
+  nxsched_usleep(100 * 1000);
 
   /* Paragraph 2.3.9:
    *
@@ -3905,7 +3905,7 @@ static int imxrt_rh_enumerate(struct usbhost_connection_s *conn,
    * 50 ms."
    */
 
-  nxsig_usleep(50 * 1000);
+  nxsched_usleep(50 * 1000);
 
   regval  = imxrt_getreg(regaddr);
   regval &= ~EHCI_PORTSC_RESET;
@@ -3926,7 +3926,7 @@ static int imxrt_rh_enumerate(struct usbhost_connection_s *conn,
    */
 
   while ((imxrt_getreg(regaddr) & EHCI_PORTSC_RESET) != 0);
-  nxsig_usleep(200 * 1000);
+  nxsched_usleep(200 * 1000);
 
   /* EHCI Paragraph 4.2.2:
    *
diff --git a/arch/arm/src/imxrt/imxrt_enet.c b/arch/arm/src/imxrt/imxrt_enet.c
index 72efc465b64..9b6656ea453 100644
--- a/arch/arm/src/imxrt/imxrt_enet.c
+++ b/arch/arm/src/imxrt/imxrt_enet.c
@@ -2226,7 +2226,7 @@ static int imxrt_determine_phy(struct imxrt_driver_s *priv)
           retries = 0;
           do
             {
-              nxsig_usleep(100);
+              nxsched_usleep(100);
               phydata = 0xffff;
               ret = imxrt_readmii(priv, phyaddr, MII_PHYID1, &phydata);
             }
@@ -2237,7 +2237,7 @@ static int imxrt_determine_phy(struct imxrt_driver_s *priv)
             {
               do
                 {
-                  nxsig_usleep(100);
+                  nxsched_usleep(100);
                   phydata = 0xffff;
                   ret = imxrt_readmii(priv, phyaddr, MII_PHYID2, &phydata);
                 }
@@ -2550,7 +2550,7 @@ static inline int imxrt_initphy(struct imxrt_driver_s *priv, bool renogphy)
       retries = 0;
       do
         {
-          nxsig_usleep(LINK_WAITUS);
+          nxsched_usleep(LINK_WAITUS);
 
           ninfo("%s: Read PHYID1, retries=%d\n",
                 BOARD_PHY_NAME, retries + 1);
@@ -2786,7 +2786,7 @@ static inline int imxrt_initphy(struct imxrt_driver_s *priv, bool renogphy)
                   break;
                 }
 
-              nxsig_usleep(LINK_WAITUS);
+              nxsched_usleep(LINK_WAITUS);
             }
 
           if (phydata & MII_MSR_ANEGCOMPLETE)
diff --git a/arch/arm/src/kinetis/kinetis_enet.c b/arch/arm/src/kinetis/kinetis_enet.c
index 322f360db6f..c1b50936095 100644
--- a/arch/arm/src/kinetis/kinetis_enet.c
+++ b/arch/arm/src/kinetis/kinetis_enet.c
@@ -1564,7 +1564,7 @@ static inline int kinetis_initphy(struct kinetis_driver_s *priv)
       retries = 0;
       do
         {
-          nxsig_usleep(LINK_WAITUS);
+          nxsched_usleep(LINK_WAITUS);
           ninfo("%s: Read PHYID1, retries=%d\n",
                 BOARD_PHY_NAME, retries + 1);
           phydata = 0xffff;
@@ -1646,7 +1646,7 @@ static inline int kinetis_initphy(struct kinetis_driver_s *priv)
           break;
         }
 
-      nxsig_usleep(LINK_WAITUS);
+      nxsched_usleep(LINK_WAITUS);
     }
 
   if (phydata & MII_MSR_ANEGCOMPLETE)
diff --git a/arch/arm/src/kinetis/kinetis_usbhshost.c b/arch/arm/src/kinetis/kinetis_usbhshost.c
index d7d5b140d29..8654f8c9699 100644
--- a/arch/arm/src/kinetis/kinetis_usbhshost.c
+++ b/arch/arm/src/kinetis/kinetis_usbhshost.c
@@ -3696,7 +3696,7 @@ static int kinetis_rh_enumerate(struct usbhost_connection_s *conn,
    * reset for 50Msec, not wait 50Msec before resetting.
    */
 
-  nxsig_usleep(100 * 1000);
+  nxsched_usleep(100 * 1000);
 
   /* Paragraph 2.3.9:
    *
@@ -3800,7 +3800,7 @@ static int kinetis_rh_enumerate(struct usbhost_connection_s *conn,
    */
 
   while ((kinetis_getreg(regaddr) & EHCI_PORTSC_RESET) != 0);
-  nxsig_usleep(200 * 1000);
+  nxsched_usleep(200 * 1000);
 
   /* EHCI Paragraph 4.2.2:
    *
diff --git a/arch/arm/src/lc823450/lc823450_i2c.c b/arch/arm/src/lc823450/lc823450_i2c.c
index 82a2891c923..6b7c45429eb 100644
--- a/arch/arm/src/lc823450/lc823450_i2c.c
+++ b/arch/arm/src/lc823450/lc823450_i2c.c
@@ -1024,7 +1024,7 @@ static int lc823450_i2c_transfer(struct i2c_master_s *dev,
            * transaction, STOP condition for write transaction
            */
 
-          nxsig_usleep(10 * 1000);
+          nxsched_usleep(10 * 1000);
         }
       else
         {
diff --git a/arch/arm/src/lc823450/lc823450_i2s.c b/arch/arm/src/lc823450/lc823450_i2s.c
index 5e2dd5ee2bf..7f51321d823 100644
--- a/arch/arm/src/lc823450/lc823450_i2s.c
+++ b/arch/arm/src/lc823450/lc823450_i2s.c
@@ -291,7 +291,7 @@ static void _setup_audio_pll(uint32_t freq)
 
   /* TODO: Wait */
 
-  nxsig_usleep(50 * 1000);
+  nxsched_usleep(50 * 1000);
 
   /* Switch to the PLL */
 
@@ -1052,7 +1052,7 @@ struct i2s_dev_s *lc823450_i2sdev_initialize(void)
   /* Set the new affinity which assigns to CPU0 */
 
   nxsched_set_affinity(nxsched_gettid(), sizeof(cpuset1), &cpuset1);
-  nxsig_usleep(10 * 1000);
+  nxsched_usleep(10 * 1000);
 #endif
 
   irq_attach(LC823450_IRQ_AUDIOBUF0, _i2s_isr, NULL);
@@ -1065,7 +1065,7 @@ struct i2s_dev_s *lc823450_i2sdev_initialize(void)
   /* Restore the original affinity */
 
   nxsched_set_affinity(nxsched_gettid(), sizeof(cpuset0), &cpuset0);
-  nxsig_usleep(10 * 1000);
+  nxsched_usleep(10 * 1000);
 #endif
 
   /* Success exit */
diff --git a/arch/arm/src/lc823450/lc823450_ipl2.c b/arch/arm/src/lc823450/lc823450_ipl2.c
index a2829268334..dead80b960c 100644
--- a/arch/arm/src/lc823450/lc823450_ipl2.c
+++ b/arch/arm/src/lc823450/lc823450_ipl2.c
@@ -357,7 +357,7 @@ static int check_forceusbboot(void)
   modifyreg32(MCLKCNTAPB, 0, MCLKCNTAPB_ADC_CLKEN);
   modifyreg32(MRSTCNTAPB, 0, MRSTCNTAPB_ADC_RSTB);
 
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
 
   /* start ADC0,1 */
 
@@ -416,7 +416,7 @@ static void sysreset(void)
 {
   /* workaround to flush eMMC cache */
 
-  nxsig_usleep(100000);
+  nxsched_usleep(100000);
 
   up_systemreset();
 }
@@ -520,7 +520,7 @@ static void chg_disable(void)
             }
           else
             {
-              nxsig_usleep(20);
+              nxsched_usleep(20);
             }
         }
 
@@ -568,7 +568,7 @@ static int msc_enable(int forced)
           return 0;
         }
 
-      nxsig_usleep(10000);
+      nxsched_usleep(10000);
     }
 
 #else
@@ -576,7 +576,7 @@ static int msc_enable(int forced)
 
   while (g_update_flag == 0)
     {
-      nxsig_usleep(10000);
+      nxsched_usleep(10000);
     }
 #endif
 
@@ -585,7 +585,7 @@ static int msc_enable(int forced)
   /* check recovery kernel update */
 
   nx_mount(CONFIG_MTD_CP_DEVPATH, "/mnt/sd0", "evfat", 0, NULL);
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
 
   /* recovery kernel install from UPG.img */
 
@@ -677,7 +677,7 @@ int ipl2_main(int argc, char *argv[])
       /* check recovery kernel update */
 
       nx_mount(CONFIG_MTD_CP_DEVPATH, "/mnt/sd0", "evfat", 0, NULL);
-      nxsig_usleep(10000);
+      nxsched_usleep(10000);
 
       /* recovery kernel install from UPG.img */
 
diff --git a/arch/arm/src/lc823450/lc823450_sddrv_dep.c b/arch/arm/src/lc823450/lc823450_sddrv_dep.c
index 5f39bdf5d7a..86cdf7f2a04 100644
--- a/arch/arm/src/lc823450/lc823450_sddrv_dep.c
+++ b/arch/arm/src/lc823450/lc823450_sddrv_dep.c
@@ -182,7 +182,7 @@ SINT_T sddep1_hw_init(struct sddrcfg_s *cfg)
 
   /* wait 15ms */
 
-  nxsig_usleep(15000);
+  nxsched_usleep(15000);
 
   irqstate_t flags = enter_critical_section();
 
@@ -276,7 +276,7 @@ void sddep_voltage_switch(struct sddrcfg_s *cfg)
 
   lc823450_gpio_config(GPIO_PORT0 | GPIO_PIN6 |
                        GPIO_MODE_OUTPUT | GPIO_VALUE_ONE);
-  nxsig_usleep(200 * 1000);
+  nxsched_usleep(200 * 1000);
 #endif
 }
 
@@ -333,7 +333,7 @@ SINT_T sddep_wait(UI_32 ms, struct sddrcfg_s *cfg)
     }
   else
     {
-      nxsig_usleep(ms * 1000);
+      nxsched_usleep(ms * 1000);
     }
 #endif
 
diff --git a/arch/arm/src/lc823450/lc823450_usbdev.c b/arch/arm/src/lc823450/lc823450_usbdev.c
index 2dbb89da22d..01586c2d5e3 100644
--- a/arch/arm/src/lc823450/lc823450_usbdev.c
+++ b/arch/arm/src/lc823450/lc823450_usbdev.c
@@ -1581,7 +1581,7 @@ int usbdev_register(struct usbdevclass_driver_s *driver)
 
       putreg32(~USB_DEVS_SOF, USB_DEVS);
 
-      nxsig_usleep(100000);
+      nxsched_usleep(100000);
 
       /* SOF is not arrived & D+/D- is HIGH */
 
diff --git a/arch/arm/src/lpc17xx_40xx/lpc17_40_ethernet.c b/arch/arm/src/lpc17xx_40xx/lpc17_40_ethernet.c
index 81ea81b1cd3..69cbc40efe0 100644
--- a/arch/arm/src/lpc17xx_40xx/lpc17_40_ethernet.c
+++ b/arch/arm/src/lpc17xx_40xx/lpc17_40_ethernet.c
@@ -2488,7 +2488,7 @@ static inline int lpc17_40_phyinit(struct lpc17_40_driver_s *priv)
 
   while ((lpc17_40_phyread(phyaddr, MII_DP83848C_STS) & 0x0001) == 0)
     {
-      nxsig_usleep(40000);
+      nxsched_usleep(40000);
     }
 #endif
 
diff --git a/arch/arm/src/lpc17xx_40xx/lpc17_40_usbhost.c b/arch/arm/src/lpc17xx_40xx/lpc17_40_usbhost.c
index 14606efe30c..482dbb2ba19 100644
--- a/arch/arm/src/lpc17xx_40xx/lpc17_40_usbhost.c
+++ b/arch/arm/src/lpc17xx_40xx/lpc17_40_usbhost.c
@@ -2076,7 +2076,7 @@ static int lpc17_40_rh_enumerate(struct usbhost_connection_s *conn,
 
   /* USB 2.0 spec says at least 50ms delay before port reset */
 
-  nxsig_usleep(100 * 1000);
+  nxsched_usleep(100 * 1000);
 
   /* Put RH port 1 in reset (the LPC176x supports only a single downstream
    * port).
@@ -2094,7 +2094,7 @@ static int lpc17_40_rh_enumerate(struct usbhost_connection_s *conn,
   /* Release RH port 1 from reset and wait a bit */
 
   lpc17_40_putreg(OHCI_RHPORTST_PRSC, LPC17_40_USBHOST_RHPORTST1);
-  nxsig_usleep(200 * 1000);
+  nxsched_usleep(200 * 1000);
   return OK;
 }
 
diff --git a/arch/arm/src/lpc31xx/lpc31_ehci.c b/arch/arm/src/lpc31xx/lpc31_ehci.c
index cc2469d2436..ca393c9e02a 100644
--- a/arch/arm/src/lpc31xx/lpc31_ehci.c
+++ b/arch/arm/src/lpc31xx/lpc31_ehci.c
@@ -3620,7 +3620,7 @@ static int lpc31_rh_enumerate(struct usbhost_connection_s *conn,
    * reset for 50Msec, not wait 50Msec before resetting.
    */
 
-  nxsig_usleep(100 * 1000);
+  nxsched_usleep(100 * 1000);
 
   /* Paragraph 2.3.9:
    *
@@ -3723,7 +3723,7 @@ static int lpc31_rh_enumerate(struct usbhost_connection_s *conn,
    * 50 ms."
    */
 
-  nxsig_usleep(50 * 1000);
+  nxsched_usleep(50 * 1000);
 
   regval  = lpc31_getreg(regaddr);
   regval &= ~EHCI_PORTSC_RESET;
@@ -3744,7 +3744,7 @@ static int lpc31_rh_enumerate(struct usbhost_connection_s *conn,
    */
 
   while ((lpc31_getreg(regaddr) & EHCI_PORTSC_RESET) != 0);
-  nxsig_usleep(200 * 1000);
+  nxsched_usleep(200 * 1000);
 
   /* Paragraph 4.2.2:
    *
diff --git a/arch/arm/src/lpc43xx/lpc43_ehci.c b/arch/arm/src/lpc43xx/lpc43_ehci.c
index 96af92c5660..1cb2302a998 100644
--- a/arch/arm/src/lpc43xx/lpc43_ehci.c
+++ b/arch/arm/src/lpc43xx/lpc43_ehci.c
@@ -3458,7 +3458,7 @@ static int lpc43_rh_enumerate(struct usbhost_connection_s *conn,
    * reset for 50Msec, not wait 50Msec before resetting.
    */
 
-  nxsig_usleep(100 * 1000);
+  nxsched_usleep(100 * 1000);
 
   /* Paragraph 2.3.9:
    *
@@ -3561,7 +3561,7 @@ static int lpc43_rh_enumerate(struct usbhost_connection_s *conn,
    * 50 ms."
    */
 
-  nxsig_usleep(50 * 1000);
+  nxsched_usleep(50 * 1000);
 
   regval  = lpc43_getreg(regaddr);
   regval &= ~EHCI_PORTSC_RESET;
@@ -3582,7 +3582,7 @@ static int lpc43_rh_enumerate(struct usbhost_connection_s *conn,
    */
 
   while ((lpc43_getreg(regaddr) & EHCI_PORTSC_RESET) != 0);
-  nxsig_usleep(200 * 1000);
+  nxsched_usleep(200 * 1000);
 
   /* Paragraph 4.2.2:
    *
diff --git a/arch/arm/src/lpc54xx/lpc54_usb0_ohci.c b/arch/arm/src/lpc54xx/lpc54_usb0_ohci.c
index c2b1db2f83d..ee36c7324ec 100644
--- a/arch/arm/src/lpc54xx/lpc54_usb0_ohci.c
+++ b/arch/arm/src/lpc54xx/lpc54_usb0_ohci.c
@@ -2172,7 +2172,7 @@ static int lpc54_rh_enumerate(struct usbhost_connection_s *conn,
 
   /* USB 2.0 spec says at least 50ms delay before port reset */
 
-  nxsig_usleep(100 * 1000);
+  nxsched_usleep(100 * 1000);
 
   /* Put RH port 1 in reset
    * (the LPC546x supports only a single downstream port)
@@ -2187,7 +2187,7 @@ static int lpc54_rh_enumerate(struct usbhost_connection_s *conn,
   /* Release RH port 1 from reset and wait a bit */
 
   lpc54_putreg(OHCI_RHPORTST_PRSC, LPC54_OHCI_RHPORTST1);
-  nxsig_usleep(200 * 1000);
+  nxsched_usleep(200 * 1000);
   return OK;
 }
 
diff --git a/arch/arm/src/mx8mp/mx8mp_i2c.c b/arch/arm/src/mx8mp/mx8mp_i2c.c
index 7c315b96512..6d254d55f1d 100644
--- a/arch/arm/src/mx8mp/mx8mp_i2c.c
+++ b/arch/arm/src/mx8mp/mx8mp_i2c.c
@@ -543,9 +543,9 @@ static void mx8mp_i2c_set_frequency(struct mx8mp_i2c_s *priv,
 static void mx8mp_i2c_reset_bus(struct mx8mp_i2c_s *priv)
 {
   mx8mp_i2c_disable(priv);
-  nxsig_usleep(50);
+  nxsched_usleep(50);
   mx8mp_i2c_enable(priv);
-  nxsig_usleep(50);
+  nxsched_usleep(50);
 }
 
 /****************************************************************************
@@ -679,7 +679,7 @@ error:
           break;
         }
 
-      nxsig_usleep(10);
+      nxsched_usleep(10);
     }
 
   /* Release access to I2C bus */
diff --git a/arch/arm/src/nrf53/nrf53_rptun.c b/arch/arm/src/nrf53/nrf53_rptun.c
index 9091d00ff5c..c99315abb9f 100644
--- a/arch/arm/src/nrf53/nrf53_rptun.c
+++ b/arch/arm/src/nrf53/nrf53_rptun.c
@@ -223,7 +223,7 @@ nrf53_rptun_get_resource(struct rptun_dev_s *dev)
 
       while (priv->shmem->base == 0)
         {
-          nxsig_usleep(100);
+          nxsched_usleep(100);
         }
     }
 
diff --git a/arch/arm/src/nrf91/nrf91_modem_os.c b/arch/arm/src/nrf91/nrf91_modem_os.c
index 71d7bd72b1c..df34614d987 100644
--- a/arch/arm/src/nrf91/nrf91_modem_os.c
+++ b/arch/arm/src/nrf91/nrf91_modem_os.c
@@ -389,7 +389,7 @@ int nrf_modem_os_sleep(uint32_t timeout)
 {
   /* Timeout in ms */
 
-  nxsig_usleep(timeout * 1000);
+  nxsched_usleep(timeout * 1000);
   return OK;
 }
 
diff --git a/arch/arm/src/nrf91/nrf91_modem_sock.c b/arch/arm/src/nrf91/nrf91_modem_sock.c
index 3a8b2034f94..973399d61f3 100644
--- a/arch/arm/src/nrf91/nrf91_modem_sock.c
+++ b/arch/arm/src/nrf91/nrf91_modem_sock.c
@@ -685,7 +685,7 @@ static void nrf91_usrsock_poll_work(void *arg)
         {
           while (g_usrsock.sock[pollfd->fd].recvpending == true)
             {
-              nxsig_usleep(100);
+              nxsched_usleep(100);
             }
         }
 
diff --git a/arch/arm/src/rp2040/rp2040_cyw43439.c b/arch/arm/src/rp2040/rp2040_cyw43439.c
index c80327d8059..de2bc347819 100644
--- a/arch/arm/src/rp2040/rp2040_cyw43439.c
+++ b/arch/arm/src/rp2040/rp2040_cyw43439.c
@@ -166,11 +166,11 @@ static int my_init(gspi_dev_t  *gspi)
   rp2040_gpio_setdir(rp_io->gpio_data, true);
   rp2040_gpio_put(rp_io->gpio_data, false);
 
-  nxsig_usleep(50000); /* Leave off for at least 50ms. */
+  nxsched_usleep(50000); /* Leave off for at least 50ms. */
 
   rp2040_gpio_put(rp_io->gpio_on, true);     /* power on */
 
-  nxsig_usleep(50000); /* Wait a bit to let the power come up. */
+  nxsched_usleep(50000); /* Wait a bit to let the power come up. */
 
   /* Don't let anyone else grab a PIO while we are doing so. */
 
diff --git a/arch/arm/src/rp2040/rp2040_ws2812.c b/arch/arm/src/rp2040/rp2040_ws2812.c
index 2b9e9538279..a101238dfb7 100644
--- a/arch/arm/src/rp2040/rp2040_ws2812.c
+++ b/arch/arm/src/rp2040/rp2040_ws2812.c
@@ -143,7 +143,7 @@ static void update_pixels(struct ws2812_dev_s  *dev_data)
 
   if (time_delta < 50)
     {
-      nxsig_usleep(50 - time_delta);
+      nxsched_usleep(50 - time_delta);
     }
 
   rp2040_dmastart(dma_handle, dma_complete, dev_data);
diff --git a/arch/arm/src/rp23xx/rp23xx_ws2812.c b/arch/arm/src/rp23xx/rp23xx_ws2812.c
index 7db05426ab4..ee4af76ba65 100644
--- a/arch/arm/src/rp23xx/rp23xx_ws2812.c
+++ b/arch/arm/src/rp23xx/rp23xx_ws2812.c
@@ -143,7 +143,7 @@ static void update_pixels(struct ws2812_dev_s  *dev_data)
 
   if (time_delta < 50)
     {
-      nxsig_usleep(50 - time_delta);
+      nxsched_usleep(50 - time_delta);
     }
 
   rp23xx_dmastart(dma_handle, dma_complete, dev_data);
diff --git a/arch/arm/src/rtl8720c/ameba_hci.c b/arch/arm/src/rtl8720c/ameba_hci.c
index 7e24cba6539..f446014ecc9 100644
--- a/arch/arm/src/rtl8720c/ameba_hci.c
+++ b/arch/arm/src/rtl8720c/ameba_hci.c
@@ -330,7 +330,7 @@ static int hci_load_firmware(struct file *filep)
       command[1] = 0x20;
       command[2] = 0xfc;
       buffer_size = header_size + command[3];
-      nxsig_usleep(10);
+      nxsched_usleep(10);
       ret = hci_send(filep, command, buffer_size);
       if (ret != buffer_size)
         {
diff --git a/arch/arm/src/rtl8720c/amebaz_depend.c b/arch/arm/src/rtl8720c/amebaz_depend.c
index 037fa1ab91d..0e257061988 100644
--- a/arch/arm/src/rtl8720c/amebaz_depend.c
+++ b/arch/arm/src/rtl8720c/amebaz_depend.c
@@ -400,7 +400,7 @@ void rtw_yield_os(void)
 
 void rtw_usleep_os(int us)
 {
-  nxsig_usleep(us);
+  nxsched_usleep(us);
 }
 
 void rtw_msleep_os(int ms)
diff --git a/arch/arm/src/rtl8720c/amebaz_driver.c b/arch/arm/src/rtl8720c/amebaz_driver.c
index c3d93841df7..fd89ce867ee 100644
--- a/arch/arm/src/rtl8720c/amebaz_driver.c
+++ b/arch/arm/src/rtl8720c/amebaz_driver.c
@@ -961,7 +961,7 @@ int amebaz_wl_set_mode(struct amebaz_dev_s *priv, struct iwreq *iwr)
 
           while (!rltk_wlan_running(priv->devnum))
             {
-              nxsig_usleep(1000);
+              nxsched_usleep(1000);
             }
 
           ret = amebaz_wl_disable_powersave(0);
@@ -1128,7 +1128,7 @@ static int amebaz_wl_on(int mode)
 
       while (!rltk_wlan_running(gp_wlan_dev[i]->devnum))
         {
-          nxsig_usleep(1000);
+          nxsched_usleep(1000);
         }
     }
 
diff --git a/arch/arm/src/s32k1xx/s32k1xx_enet.c b/arch/arm/src/s32k1xx/s32k1xx_enet.c
index 6a486a3346f..98b632f67c9 100644
--- a/arch/arm/src/s32k1xx/s32k1xx_enet.c
+++ b/arch/arm/src/s32k1xx/s32k1xx_enet.c
@@ -1909,7 +1909,7 @@ static inline int s32k1xx_initphy(struct s32k1xx_driver_s *priv,
       retries = 0;
       do
         {
-          nxsig_usleep(LINK_WAITUS);
+          nxsched_usleep(LINK_WAITUS);
 
           ninfo("%s: Read PHYID1, retries=%d\n",
                 BOARD_PHY_NAME, retries + 1);
@@ -2040,7 +2040,7 @@ static inline int s32k1xx_initphy(struct s32k1xx_driver_s *priv,
               break;
             }
 
-          nxsig_usleep(LINK_WAITUS);
+          nxsched_usleep(LINK_WAITUS);
         }
 
       if (phydata & MII_MSR_ANEGCOMPLETE)
diff --git a/arch/arm/src/s32k3xx/s32k3xx_emac.c b/arch/arm/src/s32k3xx/s32k3xx_emac.c
index 65ee3bdb260..459367f07a3 100644
--- a/arch/arm/src/s32k3xx/s32k3xx_emac.c
+++ b/arch/arm/src/s32k3xx/s32k3xx_emac.c
@@ -2805,7 +2805,7 @@ static inline int s32k3xx_initphy(struct s32k3xx_driver_s *priv,
       retries = 0;
       do
         {
-          nxsig_usleep(LINK_WAITUS);
+          nxsched_usleep(LINK_WAITUS);
 
           ninfo("%s: Read PHYID1, retries=%d\n",
                 BOARD_PHY_NAME, retries + 1);
@@ -2962,7 +2962,7 @@ static inline int s32k3xx_initphy(struct s32k3xx_driver_s *priv,
               break;
             }
 
-          nxsig_usleep(LINK_WAITUS);
+          nxsched_usleep(LINK_WAITUS);
         }
 
       if (phydata & MII_MSR_ANEGCOMPLETE)
diff --git a/arch/arm/src/sam34/sam_hsmci.c b/arch/arm/src/sam34/sam_hsmci.c
index b925a291b8f..deae1fcba49 100644
--- a/arch/arm/src/sam34/sam_hsmci.c
+++ b/arch/arm/src/sam34/sam_hsmci.c
@@ -1792,7 +1792,7 @@ static int sam_sendcmd(struct sdio_dev_s *dev,
    * correct solution.
    */
 
-  nxsig_usleep(10);
+  nxsched_usleep(10);
 
   return OK;
 }
diff --git a/arch/arm/src/sam34/sam_udp.c b/arch/arm/src/sam34/sam_udp.c
index 1151ea649f9..e4edf10427b 100644
--- a/arch/arm/src/sam34/sam_udp.c
+++ b/arch/arm/src/sam34/sam_udp.c
@@ -3524,7 +3524,7 @@ static int sam_wakeup(struct usbdev_s *dev)
 
   /* Wait 5msec in case we just entered the resume state */
 
-  nxsig_usleep(5 * 1000);
+  nxsched_usleep(5 * 1000);
 
   /* Set the ESR bit to send the remote resume */
 
diff --git a/arch/arm/src/sama5/sam_classd.c b/arch/arm/src/sama5/sam_classd.c
index 494a11dde8b..99aab249dc6 100644
--- a/arch/arm/src/sama5/sam_classd.c
+++ b/arch/arm/src/sama5/sam_classd.c
@@ -668,7 +668,7 @@ void classd_enable_audio(struct classd_dev_s *priv, bool pmc_clock_enable)
 
   /* wait for Audio PLL startup time */
 
-  nxsig_usleep(100);
+  nxsched_usleep(100);
 #endif
 }
 
diff --git a/arch/arm/src/sama5/sam_ehci.c b/arch/arm/src/sama5/sam_ehci.c
index 35e927c5613..4e5a1032723 100644
--- a/arch/arm/src/sama5/sam_ehci.c
+++ b/arch/arm/src/sama5/sam_ehci.c
@@ -3394,7 +3394,7 @@ static int sam_rh_enumerate(struct usbhost_connection_s *conn,
    * reset for 50Msec, not wait 50Msec before resetting.
    */
 
-  nxsig_usleep(100 * 1000);
+  nxsched_usleep(100 * 1000);
 
   /* Paragraph 2.3.9:
    *
@@ -3504,7 +3504,7 @@ static int sam_rh_enumerate(struct usbhost_connection_s *conn,
    * 50 ms."
    */
 
-  nxsig_usleep(50 * 1000);
+  nxsched_usleep(50 * 1000);
 
   regval  = sam_getreg(regaddr);
   regval &= ~EHCI_PORTSC_RESET;
@@ -3525,7 +3525,7 @@ static int sam_rh_enumerate(struct usbhost_connection_s *conn,
    */
 
   while ((sam_getreg(regaddr) & EHCI_PORTSC_RESET) != 0);
-  nxsig_usleep(200 * 1000);
+  nxsched_usleep(200 * 1000);
 
   /* Paragraph 4.2.2:
    *
diff --git a/arch/arm/src/sama5/sam_sdmmc.c b/arch/arm/src/sama5/sam_sdmmc.c
index 4ac441f8b32..cee5ddb3419 100644
--- a/arch/arm/src/sama5/sam_sdmmc.c
+++ b/arch/arm/src/sama5/sam_sdmmc.c
@@ -1581,7 +1581,7 @@ static void sam_reset(struct sdio_dev_s *dev)
         }
 
       timeout_ms--;
-      nxsig_usleep(100);
+      nxsched_usleep(100);
     }
 
     mcinfo("Reset complete\n");
@@ -1967,7 +1967,7 @@ static void sam_clock(struct sdio_dev_s *dev, enum sdio_clock_e rate)
 
   if (wait_microseconds > 0)
     {
-     nxsig_usleep(wait_microseconds);
+     nxsched_usleep(wait_microseconds);
     }
 }
 
@@ -2677,7 +2677,7 @@ static int sam_recvshortcrc(struct sdio_dev_s *dev, uint32_t cmd,
 
   /* We need a short delay here to let the SDMMC peripheral respond */
 
-  nxsig_usleep(10);
+  nxsched_usleep(10);
 
   return ret;
 }
@@ -3326,7 +3326,7 @@ static int sam_set_clock(struct sam_dev_s *priv, uint32_t clock)
         }
 
         timeout--;
-        nxsig_usleep(100);
+        nxsched_usleep(100);
     }
 
   sam_putreg16(priv, 0, SAMA5_SDMMC_SYSCTL_OFFSET);
@@ -3436,7 +3436,7 @@ static int sam_set_clock(struct sam_dev_s *priv, uint32_t clock)
             }
 
           timeout--;
-          nxsig_usleep(100);
+          nxsched_usleep(100);
         }
 
       /* High Speed Mode? */
diff --git a/arch/arm/src/samd5e5/sam_usb.c b/arch/arm/src/samd5e5/sam_usb.c
index 0cae30c27de..885b855ce43 100644
--- a/arch/arm/src/samd5e5/sam_usb.c
+++ b/arch/arm/src/samd5e5/sam_usb.c
@@ -5690,7 +5690,7 @@ static ssize_t sam_out_transfer(struct sam_usbhost_s *priv,
            * using the same buffer pointer and length.
            */
 
-          nxsig_usleep(20 * 1000);
+          nxsched_usleep(20 * 1000);
         }
       else
         {
@@ -6464,7 +6464,7 @@ static ssize_t sam_in_transfer(struct sam_usbhost_s *priv,
        *
        * Small delays could require more resolution than is provided
        * by the system timer.  For example, if the system timer
-       * resolution is 10MS, then nxsig_usleep(1000) will actually request
+       * resolution is 10MS, then nxsched_usleep(1000) will actually request
        * a delay 20MS (due to both quantization and rounding).
        *
        * REVISIT: So which is better?  To ignore tiny delays and
@@ -6474,7 +6474,7 @@ static ssize_t sam_in_transfer(struct sam_usbhost_s *priv,
 
                   if (delay > CONFIG_USEC_PER_TICK)
                     {
-                      nxsig_usleep(delay - CONFIG_USEC_PER_TICK);
+                      nxsched_usleep(delay - CONFIG_USEC_PER_TICK);
                     }
                 }
             }
@@ -6850,7 +6850,7 @@ static int sam_rh_enumerate(struct sam_usbhost_s *priv,
 
   /* USB 2.0 spec says at least 50ms delay before port reset. */
 
-  nxsig_usleep(100 * 1000);
+  nxsched_usleep(100 * 1000);
 
   /* Reset the host port */
 
diff --git a/arch/arm/src/samv7/sam_serial_spi.c b/arch/arm/src/samv7/sam_serial_spi.c
index b6ec15f8346..9622e7050e7 100644
--- a/arch/arm/src/samv7/sam_serial_spi.c
+++ b/arch/arm/src/samv7/sam_serial_spi.c
@@ -246,7 +246,7 @@ static inline void serial_flush(struct sam_serial_spi_s *priv)
   status = serial_getreg(priv, SAM_UART_SR_OFFSET);
   while ((status & UART_INT_TXRDY) == 0)
     {
-      nxsig_usleep(100);
+      nxsched_usleep(100);
       status = serial_getreg(priv, SAM_UART_SR_OFFSET);
     }
 
@@ -639,7 +639,7 @@ static void serial_spi_exchange(struct spi_dev_s *dev, const void *txbuffer,
       status = serial_getreg(priv, SAM_UART_SR_OFFSET);
       while ((status & UART_INT_TXRDY) == 0)
         {
-          nxsig_usleep(100);
+          nxsched_usleep(100);
           status = serial_getreg(priv, SAM_UART_SR_OFFSET);
         }
 
@@ -652,7 +652,7 @@ static void serial_spi_exchange(struct spi_dev_s *dev, const void *txbuffer,
       status = serial_getreg(priv, SAM_UART_SR_OFFSET);
       while ((status & UART_INT_RXRDY) == 0)
         {
-          nxsig_usleep(100);
+          nxsched_usleep(100);
           status = serial_getreg(priv, SAM_UART_SR_OFFSET);
         }
 
diff --git a/arch/arm/src/stm32/stm32_dfumode.c b/arch/arm/src/stm32/stm32_dfumode.c
index e002e57c453..6cef2dc9db0 100644
--- a/arch/arm/src/stm32/stm32_dfumode.c
+++ b/arch/arm/src/stm32/stm32_dfumode.c
@@ -61,7 +61,7 @@ void stm32_dfumode(void)
 {
 #ifdef CONFIG_DEBUG_WARN
   _warn("Entering DFU mode...\n");
-  nxsig_sleep(1);
+  nxsched_sleep(1);
 #endif
 
   asm("ldr r0, =0x40023844\n\t"    /* RCC_APB2ENR */
diff --git a/arch/arm/src/stm32/stm32_otgfshost.c b/arch/arm/src/stm32/stm32_otgfshost.c
index 6f88e17aafe..faa3083fe5e 100644
--- a/arch/arm/src/stm32/stm32_otgfshost.c
+++ b/arch/arm/src/stm32/stm32_otgfshost.c
@@ -1947,7 +1947,7 @@ static ssize_t stm32_in_transfer(struct stm32_usbhost_s *priv, int chidx,
                    * Small delays could require more resolution than is
                    * provided by the system timer.  For example, if the
                    * system timer resolution is 10MS, then
-                   * nxsig_usleep(1000) will actually request a delay 20MS
+                   * nxsched_usleep(1000) will actually request a delay 20MS
                    * (due to both quantization and rounding).
                    *
                    * REVISIT: So which is better?  To ignore tiny delays and
@@ -1957,7 +1957,7 @@ static ssize_t stm32_in_transfer(struct stm32_usbhost_s *priv, int chidx,
 
                   if (delay > CONFIG_USEC_PER_TICK)
                     {
-                      nxsig_usleep(delay - CONFIG_USEC_PER_TICK);
+                      nxsched_usleep(delay - CONFIG_USEC_PER_TICK);
                     }
                 }
             }
@@ -2262,7 +2262,7 @@ static ssize_t stm32_out_transfer(struct stm32_usbhost_s *priv,
            * transfer using the same buffer pointer and length.
            */
 
-          nxsig_usleep(20 * 1000);
+          nxsched_usleep(20 * 1000);
         }
       else
         {
@@ -3958,7 +3958,7 @@ static int stm32_rh_enumerate(struct stm32_usbhost_s *priv,
    * 100ms.
    */
 
-  nxsig_usleep(100 * 1000);
+  nxsched_usleep(100 * 1000);
 
   /* Reset the host port */
 
diff --git a/arch/arm/src/stm32/stm32_otghshost.c b/arch/arm/src/stm32/stm32_otghshost.c
index 32d59765f6b..5c56def26f7 100644
--- a/arch/arm/src/stm32/stm32_otghshost.c
+++ b/arch/arm/src/stm32/stm32_otghshost.c
@@ -1948,7 +1948,7 @@ static ssize_t stm32_in_transfer(struct stm32_usbhost_s *priv, int chidx,
                    * Small delays could require more resolution than is
                    * provided by the system timer.  For example, if the
                    * system timer resolution is 10MS, then
-                   * nxsig_usleep(1000) will actually request a delay 20MS
+                   * nxsched_usleep(1000) will actually request a delay 20MS
                    * (due to both quantization and rounding).
                    *
                    * REVISIT: So which is better?  To ignore tiny delays and
@@ -1958,7 +1958,7 @@ static ssize_t stm32_in_transfer(struct stm32_usbhost_s *priv, int chidx,
 
                   if (delay > CONFIG_USEC_PER_TICK)
                     {
-                      nxsig_usleep(delay - CONFIG_USEC_PER_TICK);
+                      nxsched_usleep(delay - CONFIG_USEC_PER_TICK);
                     }
                 }
             }
@@ -2263,7 +2263,7 @@ static ssize_t stm32_out_transfer(struct stm32_usbhost_s *priv,
            * transfer using the same buffer pointer and length.
            */
 
-          nxsig_usleep(20 * 1000);
+          nxsched_usleep(20 * 1000);
         }
       else
         {
@@ -3959,7 +3959,7 @@ static int stm32_rh_enumerate(struct stm32_usbhost_s *priv,
    * 100ms.
    */
 
-  nxsig_usleep(100 * 1000);
+  nxsched_usleep(100 * 1000);
 
   /* Reset the host port */
 
diff --git a/arch/arm/src/stm32f7/stm32_ethernet.c b/arch/arm/src/stm32f7/stm32_ethernet.c
index 9f4686e794b..174c3a9c958 100644
--- a/arch/arm/src/stm32f7/stm32_ethernet.c
+++ b/arch/arm/src/stm32f7/stm32_ethernet.c
@@ -3195,7 +3195,7 @@ static int stm32_phyinit(struct stm32_ethmac_s *priv)
           break;
         }
 
-      nxsig_usleep(100);
+      nxsched_usleep(100);
     }
 
   if (timeout >= PHY_RETRY_TIMEOUT)
@@ -3228,7 +3228,7 @@ static int stm32_phyinit(struct stm32_ethmac_s *priv)
           break;
         }
 
-      nxsig_usleep(100);
+      nxsched_usleep(100);
     }
 
   if (timeout >= PHY_RETRY_TIMEOUT)
diff --git a/arch/arm/src/stm32f7/stm32_otghost.c b/arch/arm/src/stm32f7/stm32_otghost.c
index 58d61392192..b1191dadd5d 100644
--- a/arch/arm/src/stm32f7/stm32_otghost.c
+++ b/arch/arm/src/stm32f7/stm32_otghost.c
@@ -1935,7 +1935,7 @@ static ssize_t stm32_in_transfer(struct stm32_usbhost_s *priv, int chidx,
                    * Small delays could require more resolution than is
                    * provided by the system timer.  For example, if the
                    * system timer resolution is 10MS, then
-                   * nxsig_usleep(1000) will actually request a delay 20MS
+                   * nxsched_usleep(1000) will actually request a delay 20MS
                    * (due to both quantization and rounding).
                    *
                    * REVISIT: So which is better?  To ignore tiny delays and
@@ -1945,7 +1945,7 @@ static ssize_t stm32_in_transfer(struct stm32_usbhost_s *priv, int chidx,
 
                   if (delay > CONFIG_USEC_PER_TICK)
                     {
-                      nxsig_usleep(delay - CONFIG_USEC_PER_TICK);
+                      nxsched_usleep(delay - CONFIG_USEC_PER_TICK);
                     }
                 }
             }
@@ -2250,7 +2250,7 @@ static ssize_t stm32_out_transfer(struct stm32_usbhost_s *priv,
            * transfer using the same buffer pointer and length.
            */
 
-          nxsig_usleep(20 * 1000);
+          nxsched_usleep(20 * 1000);
         }
       else
         {
@@ -3934,7 +3934,7 @@ static int stm32_rh_enumerate(struct stm32_usbhost_s *priv,
    * 100ms.
    */
 
-  nxsig_usleep(100 * 1000);
+  nxsched_usleep(100 * 1000);
 
   /* Reset the host port */
 
diff --git a/arch/arm/src/stm32h5/stm32_ethernet.c b/arch/arm/src/stm32h5/stm32_ethernet.c
index a0f0f7317f1..8db3d159717 100644
--- a/arch/arm/src/stm32h5/stm32_ethernet.c
+++ b/arch/arm/src/stm32h5/stm32_ethernet.c
@@ -3375,7 +3375,7 @@ static int stm32_phyinit(struct stm32_ethmac_s *priv)
           break;
         }
 
-      nxsig_usleep(100);
+      nxsched_usleep(100);
     }
 
   if (timeout >= PHY_RETRY_TIMEOUT)
@@ -3409,7 +3409,7 @@ static int stm32_phyinit(struct stm32_ethmac_s *priv)
           break;
         }
 
-      nxsig_usleep(100);
+      nxsched_usleep(100);
     }
 
   if (timeout >= PHY_RETRY_TIMEOUT)
diff --git a/arch/arm/src/stm32h7/stm32_ethernet.c b/arch/arm/src/stm32h7/stm32_ethernet.c
index 2f184c85220..e90fb5c5716 100644
--- a/arch/arm/src/stm32h7/stm32_ethernet.c
+++ b/arch/arm/src/stm32h7/stm32_ethernet.c
@@ -3338,7 +3338,7 @@ static int stm32_phyinit(struct stm32_ethmac_s *priv)
           break;
         }
 
-      nxsig_usleep(100);
+      nxsched_usleep(100);
     }
 
   if (timeout >= PHY_RETRY_TIMEOUT)
@@ -3373,7 +3373,7 @@ static int stm32_phyinit(struct stm32_ethmac_s *priv)
           break;
         }
 
-      nxsig_usleep(100);
+      nxsched_usleep(100);
     }
 
   if (timeout >= PHY_RETRY_TIMEOUT)
diff --git a/arch/arm/src/stm32h7/stm32_otghost.c b/arch/arm/src/stm32h7/stm32_otghost.c
index 033de865676..f2556448408 100644
--- a/arch/arm/src/stm32h7/stm32_otghost.c
+++ b/arch/arm/src/stm32h7/stm32_otghost.c
@@ -1962,7 +1962,7 @@ static ssize_t stm32_in_transfer(struct stm32_usbhost_s *priv, int chidx,
                    * Small delays could require more resolution than is
                    * provided by the system timer.  For example, if the
                    * system timer resolution is 10MS, then
-                   * nxsig_usleep(1000) will actually request a delay 20MS
+                   * nxsched_usleep(1000) will actually request a delay 20MS
                    * (due to both quantization and rounding).
                    *
                    * REVISIT: So which is better?  To ignore tiny delays and
@@ -1972,7 +1972,7 @@ static ssize_t stm32_in_transfer(struct stm32_usbhost_s *priv, int chidx,
 
                   if (delay > CONFIG_USEC_PER_TICK)
                     {
-                      nxsig_usleep(delay - CONFIG_USEC_PER_TICK);
+                      nxsched_usleep(delay - CONFIG_USEC_PER_TICK);
                     }
                 }
             }
@@ -2277,7 +2277,7 @@ static ssize_t stm32_out_transfer(struct stm32_usbhost_s *priv,
            * transfer using the same buffer pointer and length.
            */
 
-          nxsig_usleep(20 * 1000);
+          nxsched_usleep(20 * 1000);
         }
       else
         {
@@ -3960,7 +3960,7 @@ static int stm32_rh_enumerate(struct stm32_usbhost_s *priv,
    * 100ms.
    */
 
-  nxsig_usleep(100 * 1000);
+  nxsched_usleep(100 * 1000);
 
   /* Reset the host port */
 
diff --git a/arch/arm/src/stm32h7/stm32_rptun.c b/arch/arm/src/stm32h7/stm32_rptun.c
index c68f4a89482..0c9584a8079 100644
--- a/arch/arm/src/stm32h7/stm32_rptun.c
+++ b/arch/arm/src/stm32h7/stm32_rptun.c
@@ -228,7 +228,7 @@ stm32_rptun_get_resource(struct rptun_dev_s *dev)
 
       while (priv->shmem->base == 0)
         {
-          nxsig_usleep(100);
+          nxsched_usleep(100);
         }
     }
 
diff --git a/arch/arm/src/stm32h7/stm32_sdmmc.c b/arch/arm/src/stm32h7/stm32_sdmmc.c
index 6a2dc98d6bc..f8c252a16da 100644
--- a/arch/arm/src/stm32h7/stm32_sdmmc.c
+++ b/arch/arm/src/stm32h7/stm32_sdmmc.c
@@ -1927,11 +1927,11 @@ static void stm32_reset(struct sdio_dev_s *dev)
 
   regval = getreg32(regaddress);
   putreg32(regval | restval, regaddress);
-  nxsig_usleep(2);
+  nxsched_usleep(2);
   putreg32(regval, regaddress);
 
   stm32_setpwrctrl(priv, STM32_SDMMC_POWER_PWRCTRL_CYCLE);
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Put SDIO registers in their default, reset state */
 
@@ -1960,7 +1960,7 @@ static void stm32_reset(struct sdio_dev_s *dev)
   /* Configure the SDIO peripheral */
 
   stm32_setpwrctrl(priv, STM32_SDMMC_POWER_PWRCTRL_OFF);
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
   stm32_setpwrctrl(priv, STM32_SDMMC_POWER_PWRCTRL_ON);
 
   stm32_setclkcr(priv, STM32_CLCKCR_INIT);
diff --git a/arch/arm/src/stm32l4/stm32l4_otgfshost.c b/arch/arm/src/stm32l4/stm32l4_otgfshost.c
index 3442697642e..f1f4432337f 100644
--- a/arch/arm/src/stm32l4/stm32l4_otgfshost.c
+++ b/arch/arm/src/stm32l4/stm32l4_otgfshost.c
@@ -1951,7 +1951,7 @@ static ssize_t stm32l4_in_transfer(struct stm32l4_usbhost_s *priv,
                    * Small delays could require more resolution than is
                    * provided by the system timer.  For example, if the
                    * system timer resolution is 10MS, then
-                   * nxsig_usleep(1000) will actually request a delay 20MS
+                   * nxsched_usleep(1000) will actually request a delay 20MS
                    * (due to both quantization and rounding).
                    *
                    * REVISIT: So which is better?  To ignore tiny delays and
@@ -1961,7 +1961,7 @@ static ssize_t stm32l4_in_transfer(struct stm32l4_usbhost_s *priv,
 
                   if (delay > CONFIG_USEC_PER_TICK)
                     {
-                      nxsig_usleep(delay - CONFIG_USEC_PER_TICK);
+                      nxsched_usleep(delay - CONFIG_USEC_PER_TICK);
                     }
                 }
             }
@@ -2267,7 +2267,7 @@ static ssize_t stm32l4_out_transfer(struct stm32l4_usbhost_s *priv,
            * transfer using the same buffer pointer and length.
            */
 
-          nxsig_usleep(20 * 1000);
+          nxsched_usleep(20 * 1000);
         }
       else
         {
@@ -3961,7 +3961,7 @@ static int stm32l4_rh_enumerate(struct stm32l4_usbhost_s *priv,
    * 100ms.
    */
 
-  nxsig_usleep(100 * 1000);
+  nxsched_usleep(100 * 1000);
 
   /* Reset the host port */
 
diff --git a/arch/arm/src/tiva/common/tiva_adclow.c b/arch/arm/src/tiva/common/tiva_adclow.c
index 4081c3b8c71..a64a37f23d0 100644
--- a/arch/arm/src/tiva/common/tiva_adclow.c
+++ b/arch/arm/src/tiva/common/tiva_adclow.c
@@ -603,7 +603,7 @@ static int tiva_adc_ioctl(struct adc_dev_s *dev, int cmd, unsigned long arg)
           tiva_adc_proc_trig(priv->devno, (uint8_t)SSE_PROC_TRIG(sse));
           while (!tiva_adc_sse_int_status(priv->devno, sse))
             {
-              nxsig_usleep(100);
+              nxsched_usleep(100);
             }
 
           tiva_adc_sse_clear_int(priv->devno, sse);
diff --git a/arch/arm64/src/imx9/imx9_enet.c b/arch/arm64/src/imx9/imx9_enet.c
index 6a10d12fd0a..fd301dfcdb6 100644
--- a/arch/arm64/src/imx9/imx9_enet.c
+++ b/arch/arm64/src/imx9/imx9_enet.c
@@ -2172,7 +2172,7 @@ static int imx9_determine_phy(struct imx9_driver_s *priv)
           retries = 0;
           do
             {
-              nxsig_usleep(100);
+              nxsched_usleep(100);
               phydata = 0xffff;
               ret = imx9_readmii(priv, MII_PHYID1, &phydata);
               ninfo("phy %s addr %d received PHYID1 %x\n",
@@ -2186,7 +2186,7 @@ static int imx9_determine_phy(struct imx9_driver_s *priv)
             {
               do
                 {
-                  nxsig_usleep(100);
+                  nxsched_usleep(100);
                   phydata = 0xffff;
                   ret = imx9_readmii(priv, MII_PHYID2, &phydata);
                   ninfo("phy %s addr %d received PHYID2 %x\n",
@@ -2448,7 +2448,7 @@ int imx9_reset_phy(struct imx9_driver_s *priv)
   ret = -ETIMEDOUT;
   for (timeout = 0; timeout < PHY_RESET_WAIT_COUNT; timeout++)
     {
-      nxsig_usleep(100);
+      nxsched_usleep(100);
       result = imx9_readmii(priv, MII_MCR, &mcr);
       if (result < 0)
         {
@@ -2670,7 +2670,7 @@ static int imx9_phy_wait_autoneg_complete(struct imx9_driver_s *priv)
           break;
         }
 
-      nxsig_usleep(LINK_WAITUS);
+      nxsched_usleep(LINK_WAITUS);
     }
 
   if (timeout == LINK_NLOOPS)
@@ -2821,7 +2821,7 @@ static inline int imx9_initphy(struct imx9_driver_s *priv, bool renogphy)
       retries = 0;
       do
         {
-          nxsig_usleep(LINK_WAITUS);
+          nxsched_usleep(LINK_WAITUS);
 
           ninfo("%s: Read PHYID1, retries=%d\n", phy_name, retries + 1);
 
diff --git a/arch/renesas/src/rx65n/rx65n_usbhost.c b/arch/renesas/src/rx65n/rx65n_usbhost.c
index aade455f91a..040821bbb52 100644
--- a/arch/renesas/src/rx65n/rx65n_usbhost.c
+++ b/arch/renesas/src/rx65n/rx65n_usbhost.c
@@ -3921,7 +3921,7 @@ static uint16_t usb_cstd_is_set_frdy(uint16_t pipe, uint16_t fifosel,
 
       buffer = hw_usb_read_syscfg();
       buffer = hw_usb_read_syssts();
-      nxsig_usleep(1);
+      nxsched_usleep(1);
     }
 
   return RX65N_USB_FIFO_ERROR;
@@ -6287,7 +6287,7 @@ static void rx65n_usbhost_bottomhalf(void *arg)
 
   else
     {
-      nxsig_usleep(100);
+      nxsched_usleep(100);
       uwarn("WARNING: un known bottomhalf. Value is %d\n",
          bottom_half_processing);
       syslog(LOG_INFO, "WARNING: un known bottomhalf. Value is %d\n",
@@ -6445,13 +6445,13 @@ static int rx65n_usbhost_rh_enumerate(struct usbhost_connection_s *conn,
 
   /* USB 2.0 spec says at least 50ms delay before port reset */
 
-  nxsig_usleep(100 * 1000);
+  nxsched_usleep(100 * 1000);
 
   /* Put RH port 1 in reset.
    * Currently supporting only single downstream port)
    */
 
-  nxsig_usleep(200 * 1000);
+  nxsched_usleep(200 * 1000);
   return OK;
 }
 
@@ -8139,7 +8139,7 @@ static void rx65n_usbhost_disconnect(struct usbhost_driver_s *drvr,
                *
                */
 
-              nxsig_usleep(100000);
+              nxsched_usleep(100000);
             }
 
           for (i = 0; i < CONFIG_RX65N_USBHOST_NEDS; i++)
diff --git a/arch/risc-v/src/bl602/bl602_netdev.c b/arch/risc-v/src/bl602/bl602_netdev.c
index cda7d5492f2..e69b0672c04 100644
--- a/arch/risc-v/src/bl602/bl602_netdev.c
+++ b/arch/risc-v/src/bl602/bl602_netdev.c
@@ -804,9 +804,9 @@ static int bl602_net_soft_reset(void)
   int idx;
 
   wifi_mgmr_sta_disconnect();
-  nxsig_sleep(1);
+  nxsched_sleep(1);
   wifi_mgmr_api_ap_stop();
-  nxsig_sleep(1);
+  nxsched_sleep(1);
   wifi_mgmr_api_idle();
   wifi_mgmr_reset();
 
@@ -1302,7 +1302,7 @@ static int bl602_ioctl_wifi_stop(struct bl602_net_driver_s *priv,
         }
 
       wifi_mgmr_sta_disconnect();
-      nxsig_sleep(1);
+      nxsched_sleep(1);
       wifi_mgmr_api_idle();
     }
   else if (priv->current_mode == IW_MODE_MASTER)
@@ -1313,7 +1313,7 @@ static int bl602_ioctl_wifi_stop(struct bl602_net_driver_s *priv,
         }
 
       wifi_mgmr_api_ap_stop();
-      nxsig_sleep(1);
+      nxsched_sleep(1);
       wifi_mgmr_api_idle();
     }
 
diff --git a/arch/risc-v/src/bl602/bl602_os_hal.c b/arch/risc-v/src/bl602/bl602_os_hal.c
index a724ba59635..7b8e5028f2d 100644
--- a/arch/risc-v/src/bl602/bl602_os_hal.c
+++ b/arch/risc-v/src/bl602/bl602_os_hal.c
@@ -518,7 +518,9 @@ int bl_os_msleep(long msec)
 {
   useconds_t usec = msec * 1000;
 
-  return nxsig_usleep(usec);
+  nxsched_usleep(usec);
+
+  return 0;
 }
 
 /****************************************************************************
@@ -534,7 +536,9 @@ int bl_os_msleep(long msec)
 
 int bl_os_sleep(unsigned int seconds)
 {
-  return nxsig_sleep(seconds);
+  nxsched_sleep(seconds);
+
+  return 0;
 }
 
 /****************************************************************************
diff --git a/arch/risc-v/src/common/espressif/esp_i2c_slave.c b/arch/risc-v/src/common/espressif/esp_i2c_slave.c
index 764dbfcc3b1..602b10d7fa4 100644
--- a/arch/risc-v/src/common/espressif/esp_i2c_slave.c
+++ b/arch/risc-v/src/common/espressif/esp_i2c_slave.c
@@ -718,14 +718,14 @@ static int esp_i2c_slave_thread(int argc, char **argv)
       (struct esp_i2c_priv_s *)((uintptr_t)strtoul(argv[1], NULL, 16));
   int ret;
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
   while (true)
     {
       esp_i2c_slave_polling_waitdone(priv);
 
       /* Sleeping thread before checking i2c peripheral */
 
-      nxsig_usleep(100);
+      nxsched_usleep(100);
     }
 
   return OK;
diff --git a/arch/risc-v/src/common/espressif/esp_temperature_sensor.c b/arch/risc-v/src/common/espressif/esp_temperature_sensor.c
index 4ba7478d46d..7b5a8edd84c 100644
--- a/arch/risc-v/src/common/espressif/esp_temperature_sensor.c
+++ b/arch/risc-v/src/common/espressif/esp_temperature_sensor.c
@@ -683,7 +683,7 @@ static int esp_temperature_sensor_thread(int argc, char **argv)
 
       /* Sleeping thread before fetching the next sensor data */
 
-      nxsig_usleep(priv->interval);
+      nxsched_usleep(priv->interval);
     }
 
   return OK;
diff --git a/arch/risc-v/src/common/espressif/esp_wlan_netdev.c b/arch/risc-v/src/common/espressif/esp_wlan_netdev.c
index 4e35c64eeb9..c13a1425ea0 100644
--- a/arch/risc-v/src/common/espressif/esp_wlan_netdev.c
+++ b/arch/risc-v/src/common/espressif/esp_wlan_netdev.c
@@ -448,7 +448,7 @@ static int esp_wlan_connect(struct netdev_lowerhalf_s *dev)
               break;
             }
 
-          nxsig_usleep(timeout);
+          nxsched_usleep(timeout);
           timeout_count--;
         }
 
diff --git a/arch/risc-v/src/esp32c3-legacy/esp32c3_ble_adapter.c b/arch/risc-v/src/esp32c3-legacy/esp32c3_ble_adapter.c
index 88337d0a981..71c9bf9735f 100644
--- a/arch/risc-v/src/esp32c3-legacy/esp32c3_ble_adapter.c
+++ b/arch/risc-v/src/esp32c3-legacy/esp32c3_ble_adapter.c
@@ -2209,7 +2209,7 @@ int esp32c3_bt_controller_disable(void)
 
   while (!btdm_power_state_active())
     {
-      nxsig_usleep(1000); /* wait */
+      nxsched_usleep(1000); /* wait */
     }
 
   btdm_controller_disable();
diff --git a/arch/risc-v/src/esp32c3-legacy/esp32c3_twai.c b/arch/risc-v/src/esp32c3-legacy/esp32c3_twai.c
index b6c95601a27..577185c8938 100644
--- a/arch/risc-v/src/esp32c3-legacy/esp32c3_twai.c
+++ b/arch/risc-v/src/esp32c3-legacy/esp32c3_twai.c
@@ -1220,7 +1220,7 @@ struct can_dev_s *esp32c3_twaiinitialize(int port)
       modifyreg32(SYSTEM_PERIP_RST_EN0_REG, 0, SYSTEM_TWAI_RST_M);
       modifyreg32(SYSTEM_PERIP_CLK_EN0_REG, SYSTEM_TWAI_CLK_EN_M, 0);
 
-      nxsig_usleep(1);
+      nxsched_usleep(1);
 
       modifyreg32(SYSTEM_PERIP_CLK_EN0_REG, 0, SYSTEM_TWAI_CLK_EN_M);
       modifyreg32(SYSTEM_PERIP_RST_EN0_REG, SYSTEM_TWAI_RST_M, 0);
diff --git a/arch/risc-v/src/esp32c3-legacy/esp32c3_wifi_adapter.c b/arch/risc-v/src/esp32c3-legacy/esp32c3_wifi_adapter.c
index c7119ebc8bd..27fc8850d5d 100644
--- a/arch/risc-v/src/esp32c3-legacy/esp32c3_wifi_adapter.c
+++ b/arch/risc-v/src/esp32c3-legacy/esp32c3_wifi_adapter.c
@@ -2053,7 +2053,7 @@ static void esp_task_delay(uint32_t tick)
 {
   useconds_t us = TICK2USEC(tick);
 
-  nxsig_usleep(us);
+  nxsched_usleep(us);
 }
 
 /****************************************************************************
@@ -6929,6 +6929,6 @@ void esp_wifi_stop_callback(void)
     }
   else
     {
-      nxsig_sleep(1);
+      nxsched_sleep(1);
     }
 }
diff --git a/arch/risc-v/src/esp32c3/esp_ble_adapter.c b/arch/risc-v/src/esp32c3/esp_ble_adapter.c
index e6b74f04923..828b82c88ed 100644
--- a/arch/risc-v/src/esp32c3/esp_ble_adapter.c
+++ b/arch/risc-v/src/esp32c3/esp_ble_adapter.c
@@ -3405,7 +3405,7 @@ int esp_bt_controller_disable(void)
   async_wakeup_request(BTDM_ASYNC_WAKEUP_SRC_DISA);
   while (!btdm_power_state_active())
     {
-      nxsig_usleep(1000); /* wait */
+      nxsched_usleep(1000); /* wait */
     }
 
   btdm_controller_disable();
diff --git a/arch/risc-v/src/esp32c3/esp_wifi_adapter.c b/arch/risc-v/src/esp32c3/esp_wifi_adapter.c
index f1a1286ac74..2bc47339566 100644
--- a/arch/risc-v/src/esp32c3/esp_wifi_adapter.c
+++ b/arch/risc-v/src/esp32c3/esp_wifi_adapter.c
@@ -2694,7 +2694,7 @@ static void task_delay_wrapper(uint32_t tick)
 {
   useconds_t us = TICK2USEC(tick);
 
-  nxsig_usleep(us);
+  nxsched_usleep(us);
 }
 
 /****************************************************************************
diff --git a/arch/risc-v/src/esp32c6/esp_wifi_adapter.c b/arch/risc-v/src/esp32c6/esp_wifi_adapter.c
index 5110274a199..82803644235 100644
--- a/arch/risc-v/src/esp32c6/esp_wifi_adapter.c
+++ b/arch/risc-v/src/esp32c6/esp_wifi_adapter.c
@@ -2682,7 +2682,7 @@ static void task_delay_wrapper(uint32_t tick)
 {
   useconds_t us = TICK2USEC(tick);
 
-  nxsig_usleep(us);
+  nxsched_usleep(us);
 }
 
 /****************************************************************************
diff --git a/arch/risc-v/src/k230/k230_rptun.c b/arch/risc-v/src/k230/k230_rptun.c
index 360794bf55a..810a778d533 100644
--- a/arch/risc-v/src/k230/k230_rptun.c
+++ b/arch/risc-v/src/k230/k230_rptun.c
@@ -226,7 +226,7 @@ static struct rptun_rsc_s *rp_get_resource(struct rptun_dev_s *dev)
       rpinfo("wait for shmem %p...\n", priv->shmem);
       while (priv->shmem->base == 0)
         {
-          nxsig_usleep(100);
+          nxsched_usleep(100);
         }
 
       rpinfo("shmem:%lx, dev:%p\n", priv->shmem->base, dev);
diff --git a/arch/risc-v/src/litex/litex_emac.c b/arch/risc-v/src/litex/litex_emac.c
index 2537cdde605..927e3bb320d 100644
--- a/arch/risc-v/src/litex/litex_emac.c
+++ b/arch/risc-v/src/litex/litex_emac.c
@@ -776,7 +776,7 @@ static int litex_linkup(struct litex_emac_s *priv)
 
   for (i = 0; i < LITEX_WAITLINKTIMEOUT; ++i)
     {
-      nxsig_usleep(1000);
+      nxsched_usleep(1000);
 
       ret = litex_phyread(priv, priv->phyaddr, MII_MSR, &msr);
       if (ret < 0)
@@ -1292,9 +1292,9 @@ static int litex_phyinit(struct litex_emac_s *priv)
 
   ninfo("%s: PHY RESET\n", BOARD_PHY_NAME);
   putreg32(1, LITEX_ETHPHY_CRG_RESET);
-  nxsig_usleep(LITEX_PHY_RESETTIMEOUT);
+  nxsched_usleep(LITEX_PHY_RESETTIMEOUT);
   putreg32(0, LITEX_ETHPHY_CRG_RESET);
-  nxsig_usleep(LITEX_PHY_RESETTIMEOUT);
+  nxsched_usleep(LITEX_PHY_RESETTIMEOUT);
 
   /* Check the PHY responds at configured address */
 
diff --git a/arch/risc-v/src/litex/litex_sdio.c b/arch/risc-v/src/litex/litex_sdio.c
index 0fde5d1ac1f..58078d55415 100644
--- a/arch/risc-v/src/litex/litex_sdio.c
+++ b/arch/risc-v/src/litex/litex_sdio.c
@@ -955,7 +955,7 @@ static int litex_waitresponse(struct sdio_dev_s *dev, uint32_t cmd)
       if (ev & LITEX_EV_CMDDONE)
         break;
 
-      nxsig_usleep(10);
+      nxsched_usleep(10);
     }
 
   if (ev & LITEX_EV_WRERROR)
diff --git a/arch/risc-v/src/mpfs/mpfs_coremmc.c b/arch/risc-v/src/mpfs/mpfs_coremmc.c
index b7731f0406c..f05606ada55 100644
--- a/arch/risc-v/src/mpfs/mpfs_coremmc.c
+++ b/arch/risc-v/src/mpfs/mpfs_coremmc.c
@@ -1039,19 +1039,19 @@ static bool mpfs_device_reset(struct sdio_dev_s *dev)
 
   modifyreg32(MPFS_SYSREG_SUBBLK_CLOCK_CR, 0, SYSREG_SUBBLK_CLOCK_CR_FIC0);
 
-  nxsig_usleep(100);
+  nxsched_usleep(100);
 
   /* Perform module and slave reset */
 
   mpfs_modifyreg8(MPFS_COREMMC_CTRL, 0, COREMMC_CTRL_SLRST |
                   COREMMC_CTRL_SWRST);
 
-  nxsig_usleep(100);
+  nxsched_usleep(100);
 
   mpfs_modifyreg8(MPFS_COREMMC_CTRL, COREMMC_CTRL_SLRST | COREMMC_CTRL_SWRST,
                   0);
 
-  nxsig_usleep(100);
+  nxsched_usleep(100);
 
   /* Clear interrupt status and disable interrupts */
 
@@ -1067,7 +1067,7 @@ static bool mpfs_device_reset(struct sdio_dev_s *dev)
 
   mpfs_setclkrate(priv, MPFS_MMC_CLOCK_400KHZ);
 
-  nxsig_usleep(100);
+  nxsched_usleep(100);
 
   /* Store fifo size for later to check no fifo overruns occur */
 
@@ -1351,7 +1351,7 @@ static void mpfs_clock(struct sdio_dev_s *dev, enum sdio_clock_e rate)
     {
       /* Need to settle a bit before issuing this CMD6 after clk change */
 
-      nxsig_usleep(100);
+      nxsched_usleep(100);
 
       mpfs_set_4bit_mode(dev);
     }
diff --git a/arch/risc-v/src/mpfs/mpfs_dsn.c b/arch/risc-v/src/mpfs/mpfs_dsn.c
index 38ca472caa9..40012c8cac7 100644
--- a/arch/risc-v/src/mpfs/mpfs_dsn.c
+++ b/arch/risc-v/src/mpfs/mpfs_dsn.c
@@ -99,7 +99,7 @@ int mpfs_read_dsn(uint8_t *dsn, size_t len)
   while ((getreg32(SERVICES_SR) & SCBCTRL_SERVICESSR_BUSY) && --retries > 0)
     {
       spin_unlock_irqrestore(&g_dsn_lock, flags);
-      nxsig_usleep(1000);
+      nxsched_usleep(1000);
       flags = spin_lock_irqsave(&g_dsn_lock);
     }
 
diff --git a/arch/risc-v/src/mpfs/mpfs_emmcsd.c b/arch/risc-v/src/mpfs/mpfs_emmcsd.c
index 86358cf8542..2f8bf9b31d6 100644
--- a/arch/risc-v/src/mpfs/mpfs_emmcsd.c
+++ b/arch/risc-v/src/mpfs/mpfs_emmcsd.c
@@ -1298,7 +1298,7 @@ static void mpfs_set_sdhost_power(struct mpfs_dev_s *priv, uint32_t voltage)
         DEBUGPANIC();
     }
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 }
 
 /****************************************************************************
@@ -1483,13 +1483,13 @@ static bool mpfs_device_reset(struct sdio_dev_s *dev)
   modifyreg32(MPFS_SYSREG_SOFT_RESET_CR,
               SYSREG_SOFT_RESET_CR_MMC, 0);
 
-  nxsig_sleep(1);
+  nxsched_sleep(1);
 
   /* Perform module-level reset */
 
   modifyreg32(MPFS_EMMCSD_HRS00, 0, MPFS_EMMCSD_HRS00_SWR);
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   do
     {
@@ -1637,7 +1637,7 @@ static bool mpfs_device_reset(struct sdio_dev_s *dev)
       mpfs_setclkrate(priv, MPFS_MMC_CLOCK_400KHZ);
     }
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Reset data */
 
diff --git a/arch/risc-v/src/mpfs/mpfs_i2c.c b/arch/risc-v/src/mpfs/mpfs_i2c.c
index f51e16c0a07..cbcd71939d4 100644
--- a/arch/risc-v/src/mpfs/mpfs_i2c.c
+++ b/arch/risc-v/src/mpfs/mpfs_i2c.c
@@ -813,7 +813,7 @@ static int mpfs_i2c_force_idle(struct mpfs_i2c_priv_s *priv)
 
       /* Wait for a while for the command to go through */
 
-      nxsig_usleep(1000);
+      nxsched_usleep(1000);
     }
   while (retries--);
 
diff --git a/arch/risc-v/src/mpfs/mpfs_usb.c b/arch/risc-v/src/mpfs/mpfs_usb.c
index 2a6d8719983..17b7ca20d0c 100644
--- a/arch/risc-v/src/mpfs/mpfs_usb.c
+++ b/arch/risc-v/src/mpfs/mpfs_usb.c
@@ -3805,7 +3805,7 @@ static void mpfs_hw_shutdown(struct mpfs_usbdev_s *priv)
   /* Force disconnect and give some time to finish it up */
 
   mpfs_modifyreg8(MPFS_USB_POWER, POWER_REG_SOFT_CONN_MASK, 0);
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Disable all interrupts */
 
diff --git a/arch/risc-v/src/qemu-rv/qemu_rv_rptun.c b/arch/risc-v/src/qemu-rv/qemu_rv_rptun.c
index 5bfa39cbe18..5c4bdc21fff 100644
--- a/arch/risc-v/src/qemu-rv/qemu_rv_rptun.c
+++ b/arch/risc-v/src/qemu-rv/qemu_rv_rptun.c
@@ -253,7 +253,7 @@ static struct rptun_rsc_s *rp_get_resource(struct rptun_dev_s *dev)
 
       while (priv->shmem->base == 0)
         {
-          nxsig_usleep(100);
+          nxsched_usleep(100);
         }
     }
 
diff --git a/arch/risc-v/src/rp23xx-rv/rp23xx_ws2812.c b/arch/risc-v/src/rp23xx-rv/rp23xx_ws2812.c
index f04b651247a..61be57e31bd 100644
--- a/arch/risc-v/src/rp23xx-rv/rp23xx_ws2812.c
+++ b/arch/risc-v/src/rp23xx-rv/rp23xx_ws2812.c
@@ -143,7 +143,7 @@ static void update_pixels(struct ws2812_dev_s  *dev_data)
 
   if (time_delta < 50)
     {
-      nxsig_usleep(50 - time_delta);
+      nxsched_usleep(50 - time_delta);
     }
 
   rp23xx_dmastart(dma_handle, dma_complete, dev_data);
diff --git a/arch/xtensa/src/common/espressif/esp_i2c_slave.c b/arch/xtensa/src/common/espressif/esp_i2c_slave.c
index ad05d6aa920..59a6db001c7 100644
--- a/arch/xtensa/src/common/espressif/esp_i2c_slave.c
+++ b/arch/xtensa/src/common/espressif/esp_i2c_slave.c
@@ -778,14 +778,14 @@ static int esp_i2c_slave_thread(int argc, char **argv)
       (struct esp_i2c_priv_s *)((uintptr_t)strtoul(argv[1], NULL, 16));
   int ret;
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
   while (true)
     {
       esp_i2c_slave_polling_waitdone(priv);
 
       /* Sleeping thread before checking i2c peripheral */
 
-      nxsig_usleep(100);
+      nxsched_usleep(100);
     }
 
   return OK;
diff --git a/arch/xtensa/src/common/espressif/esp_temperature_sensor.c b/arch/xtensa/src/common/espressif/esp_temperature_sensor.c
index 701346b0d08..a3a72257b08 100644
--- a/arch/xtensa/src/common/espressif/esp_temperature_sensor.c
+++ b/arch/xtensa/src/common/espressif/esp_temperature_sensor.c
@@ -682,7 +682,7 @@ static int esp_temperature_sensor_thread(int argc, char **argv)
 
       /* Sleeping thread before fetching the next sensor data */
 
-      nxsig_usleep(priv->interval);
+      nxsched_usleep(priv->interval);
     }
 
   return OK;
diff --git a/arch/xtensa/src/common/espressif/esp_wlan_netdev.c b/arch/xtensa/src/common/espressif/esp_wlan_netdev.c
index 29a1dfd16db..529f1ed9d9a 100644
--- a/arch/xtensa/src/common/espressif/esp_wlan_netdev.c
+++ b/arch/xtensa/src/common/espressif/esp_wlan_netdev.c
@@ -448,7 +448,7 @@ static int esp_wlan_connect(struct netdev_lowerhalf_s *dev)
               break;
             }
 
-          nxsig_usleep(timeout);
+          nxsched_usleep(timeout);
           timeout_count--;
         }
 
diff --git a/arch/xtensa/src/esp32/esp32_ble_adapter.c b/arch/xtensa/src/esp32/esp32_ble_adapter.c
index fc71656498b..325b0e77b85 100644
--- a/arch/xtensa/src/esp32/esp32_ble_adapter.c
+++ b/arch/xtensa/src/esp32/esp32_ble_adapter.c
@@ -3237,7 +3237,7 @@ int esp32_bt_controller_disable(void)
       async_wakeup_request(BTDM_ASYNC_WAKEUP_REQ_CTRL_DISA);
       while (btdm_power_state_active() == false)
         {
-          nxsig_usleep(1000);
+          nxsched_usleep(1000);
         }
     }
 
diff --git a/arch/xtensa/src/esp32/esp32_spiflash.c b/arch/xtensa/src/esp32/esp32_spiflash.c
index 0c4d097450e..88776a8ab12 100644
--- a/arch/xtensa/src/esp32/esp32_spiflash.c
+++ b/arch/xtensa/src/esp32/esp32_spiflash.c
@@ -683,7 +683,7 @@ static inline void IRAM_ATTR esp32_spiflash_oposyield(void)
   /* Delay 1 tick */
 
   useconds_t us = TICK2USEC(1);
-  nxsig_usleep(us);
+  nxsched_usleep(us);
 }
 
 /****************************************************************************
diff --git a/arch/xtensa/src/esp32/esp32_wifi_adapter.c b/arch/xtensa/src/esp32/esp32_wifi_adapter.c
index c919bd7cb79..3fa4829ec4e 100644
--- a/arch/xtensa/src/esp32/esp32_wifi_adapter.c
+++ b/arch/xtensa/src/esp32/esp32_wifi_adapter.c
@@ -1639,7 +1639,7 @@ static void esp_task_delay(uint32_t tick)
 {
   useconds_t us = TICK2USEC(tick);
 
-  nxsig_usleep(us);
+  nxsched_usleep(us);
 }
 
 /****************************************************************************
diff --git a/arch/xtensa/src/esp32s2/esp32s2_wifi_adapter.c b/arch/xtensa/src/esp32s2/esp32s2_wifi_adapter.c
index 78a1822f625..b00f7115d1b 100644
--- a/arch/xtensa/src/esp32s2/esp32s2_wifi_adapter.c
+++ b/arch/xtensa/src/esp32s2/esp32s2_wifi_adapter.c
@@ -1574,7 +1574,7 @@ static void esp_task_delay(uint32_t tick)
 {
   useconds_t us = TICK2USEC(tick);
 
-  nxsig_usleep(us);
+  nxsched_usleep(us);
 }
 
 /****************************************************************************
diff --git a/arch/xtensa/src/esp32s3/esp32s3_ble_adapter.c b/arch/xtensa/src/esp32s3/esp32s3_ble_adapter.c
index a9840c74fef..7a2038f5742 100644
--- a/arch/xtensa/src/esp32s3/esp32s3_ble_adapter.c
+++ b/arch/xtensa/src/esp32s3/esp32s3_ble_adapter.c
@@ -3576,7 +3576,7 @@ int esp32s3_bt_controller_disable(void)
   async_wakeup_request(BTDM_ASYNC_WAKEUP_SRC_DISA);
   while (!btdm_power_state_active())
     {
-      nxsig_usleep(1000); /* wait */
+      nxsched_usleep(1000); /* wait */
     }
 
   btdm_controller_disable();
diff --git a/arch/xtensa/src/esp32s3/esp32s3_spiflash.c b/arch/xtensa/src/esp32s3/esp32s3_spiflash.c
index 4eb99822fc7..b71a35572f6 100644
--- a/arch/xtensa/src/esp32s3/esp32s3_spiflash.c
+++ b/arch/xtensa/src/esp32s3/esp32s3_spiflash.c
@@ -867,7 +867,7 @@ static inline void IRAM_ATTR spiflash_os_yield(void)
   /* Delay 1 tick */
 
   useconds_t us = TICK2USEC(1);
-  nxsig_usleep(us);
+  nxsched_usleep(us);
 }
 #endif /* CONFIG_ESP32S3_SPI_FLASH_DONT_USE_ROM_CODE */
 
diff --git a/arch/xtensa/src/esp32s3/esp32s3_wifi_adapter.c b/arch/xtensa/src/esp32s3/esp32s3_wifi_adapter.c
index 6820e1d73ca..4a2d1e91323 100644
--- a/arch/xtensa/src/esp32s3/esp32s3_wifi_adapter.c
+++ b/arch/xtensa/src/esp32s3/esp32s3_wifi_adapter.c
@@ -1637,7 +1637,7 @@ static void esp_task_delay(uint32_t tick)
 {
   useconds_t us = TICK2USEC(tick);
 
-  nxsig_usleep(us);
+  nxsched_usleep(us);
 }
 
 /****************************************************************************
diff --git a/boards/arm/cxd56xx/common/src/cxd56_audio.c b/boards/arm/cxd56xx/common/src/cxd56_audio.c
index 08fa0da9b68..14f2f0fc4f9 100644
--- a/boards/arm/cxd56xx/common/src/cxd56_audio.c
+++ b/boards/arm/cxd56xx/common/src/cxd56_audio.c
@@ -292,13 +292,13 @@ int board_external_amp_mute_control(bool en)
       /* Mute ON */
 
       ret = board_power_control(POWER_AUDIO_MUTE, false);
-      nxsig_usleep(MUTE_ON_DELAY);
+      nxsched_usleep(MUTE_ON_DELAY);
     }
   else
     {
       /* Mute OFF */
 
-      nxsig_usleep(MUTE_OFF_DELAY);
+      nxsched_usleep(MUTE_OFF_DELAY);
       ret = board_power_control(POWER_AUDIO_MUTE, true);
     }
 
diff --git a/boards/arm/cxd56xx/common/src/cxd56_bcm20706.c b/boards/arm/cxd56xx/common/src/cxd56_bcm20706.c
index 7e480151c31..6f5f8538d37 100644
--- a/boards/arm/cxd56xx/common/src/cxd56_bcm20706.c
+++ b/boards/arm/cxd56xx/common/src/cxd56_bcm20706.c
@@ -119,9 +119,9 @@ int board_bluetooth_uart_pin_cfg(void)
 void board_bluetooth_reset(void)
 {
   cxd56_gpio_write(BCM20707_RST_N, false);
-  nxsig_usleep(BCM20707_RST_DELAY);
+  nxsched_usleep(BCM20707_RST_DELAY);
   cxd56_gpio_write(BCM20707_RST_N, true);
-  nxsig_usleep(BCM20707_RST_DELAY);
+  nxsched_usleep(BCM20707_RST_DELAY);
 }
 
 /****************************************************************************
diff --git a/boards/arm/cxd56xx/common/src/cxd56_emmcdev.c b/boards/arm/cxd56xx/common/src/cxd56_emmcdev.c
index 8911357e57f..210ce7129b6 100644
--- a/boards/arm/cxd56xx/common/src/cxd56_emmcdev.c
+++ b/boards/arm/cxd56xx/common/src/cxd56_emmcdev.c
@@ -78,7 +78,7 @@ int board_emmc_initialize(void)
     {
       /* Wait time until eMMC device is turned power on */
 
-      nxsig_usleep(EMMC_POWER_ON_WAIT_MSEC * USEC_PER_MSEC);
+      nxsched_usleep(EMMC_POWER_ON_WAIT_MSEC * USEC_PER_MSEC);
     }
 
   /* Initialize the eMMC device */
diff --git a/boards/arm/cxd56xx/common/src/cxd56_isx012.c b/boards/arm/cxd56xx/common/src/cxd56_isx012.c
index 28112fe3e91..08f9a27622d 100644
--- a/boards/arm/cxd56xx/common/src/cxd56_isx012.c
+++ b/boards/arm/cxd56xx/common/src/cxd56_isx012.c
@@ -91,7 +91,7 @@ int board_isx012_power_on(void)
     {
       /* Need to wait for a while after power-on */
 
-      nxsig_usleep(POWER_CHECK_TIME);
+      nxsched_usleep(POWER_CHECK_TIME);
 
       if (true == board_power_monitor(POWER_IMAGE_SENSOR))
         {
@@ -117,7 +117,7 @@ int board_isx012_power_off(void)
 
   /* Need to wait for power-off to be reflected */
 
-  nxsig_usleep(POWER_OFF_TIME);
+  nxsched_usleep(POWER_OFF_TIME);
 
   ret = -ETIMEDOUT;
   for (i = 0; i < POWER_CHECK_RETRY; i++)
@@ -128,7 +128,7 @@ int board_isx012_power_off(void)
           break;
         }
 
-      nxsig_usleep(POWER_CHECK_TIME);
+      nxsched_usleep(POWER_CHECK_TIME);
     }
 
   return ret;
@@ -151,20 +151,20 @@ void board_isx012_set_sleep(int kind)
     {
       /* PowerON -> sleep */
 
-      nxsig_usleep(DEVICE_STARTUP_TIME);
+      nxsched_usleep(DEVICE_STARTUP_TIME);
     }
   else
     {
       /* active -> sleep */
 
-      nxsig_usleep(STANDBY_TIME);
+      nxsched_usleep(STANDBY_TIME);
     }
 }
 
 void board_isx012_release_sleep(void)
 {
   cxd56_gpio_write(IMAGER_SLEEP, true);
-  nxsig_usleep(SLEEP_CANCEL_TIME);
+  nxsched_usleep(SLEEP_CANCEL_TIME);
 }
 
 int isx012_register(struct i2c_master_s *i2c);
diff --git a/boards/arm/cxd56xx/common/src/cxd56_isx019.c b/boards/arm/cxd56xx/common/src/cxd56_isx019.c
index ce97f9e68e6..8da3813c04b 100644
--- a/boards/arm/cxd56xx/common/src/cxd56_isx019.c
+++ b/boards/arm/cxd56xx/common/src/cxd56_isx019.c
@@ -86,7 +86,7 @@ int board_isx019_power_on(void)
     {
       /* Need to wait for a while after power-on */
 
-      nxsig_usleep(POWER_CHECK_TIME);
+      nxsched_usleep(POWER_CHECK_TIME);
 
       if (board_power_monitor(POWER_IMAGE_SENSOR))
         {
@@ -112,7 +112,7 @@ int board_isx019_power_off(void)
 
   /* Need to wait for power-off to be reflected */
 
-  nxsig_usleep(POWER_OFF_TIME);
+  nxsched_usleep(POWER_OFF_TIME);
 
   ret = -ETIMEDOUT;
   for (i = 0; i < POWER_CHECK_RETRY; i++)
@@ -123,7 +123,7 @@ int board_isx019_power_off(void)
           break;
         }
 
-      nxsig_usleep(POWER_CHECK_TIME);
+      nxsched_usleep(POWER_CHECK_TIME);
     }
 
   return ret;
@@ -153,7 +153,7 @@ struct i2c_master_s *board_isx019_initialize(void)
     {
       /* ISX019 requires stable RTC */
 
-      nxsig_usleep(100 * USEC_PER_MSEC);
+      nxsched_usleep(100 * USEC_PER_MSEC);
     }
 
   cxd56_gpio_config(IMAGER_RST, false);
diff --git a/boards/arm/cxd56xx/drivers/audio/cxd56_audio_analog.c b/boards/arm/cxd56xx/drivers/audio/cxd56_audio_analog.c
index 95398b5ed88..eef34739072 100644
--- a/boards/arm/cxd56xx/drivers/audio/cxd56_audio_analog.c
+++ b/boards/arm/cxd56xx/drivers/audio/cxd56_audio_analog.c
@@ -81,7 +81,7 @@ static void wait_mic_boot_finish(void)
 
       if (time < CXD56_AUDIO_MIC_BOOT_WAIT)
         {
-          nxsig_usleep((CXD56_AUDIO_MIC_BOOT_WAIT - time) * 1000);
+          nxsched_usleep((CXD56_AUDIO_MIC_BOOT_WAIT - time) * 1000);
         }
     }
 }
diff --git a/boards/arm/cxd56xx/drivers/audio/cxd56_audio_volume.c b/boards/arm/cxd56xx/drivers/audio/cxd56_audio_volume.c
index d8bd1ac5ef5..e9d7e46dee0 100644
--- a/boards/arm/cxd56xx/drivers/audio/cxd56_audio_volume.c
+++ b/boards/arm/cxd56xx/drivers/audio/cxd56_audio_volume.c
@@ -115,7 +115,7 @@ static CXD56_AUDIO_ECODE set_mute(cxd56_audio_volid_t id,
 
   if (wait)
     {
-      nxsig_usleep(waittime);
+      nxsched_usleep(waittime);
     }
 
   g_volparam[id].mute_bit |= type;
@@ -181,7 +181,7 @@ static CXD56_AUDIO_ECODE set_unmute(cxd56_audio_volid_t id,
 
       if (wait)
         {
-          nxsig_usleep(waittime);
+          nxsched_usleep(waittime);
         }
     }
 
diff --git a/boards/arm/cxd56xx/drivers/sensors/cxd5610_gnss.c b/boards/arm/cxd56xx/drivers/sensors/cxd5610_gnss.c
index 8ead324a8bc..586186c3de0 100644
--- a/boards/arm/cxd56xx/drivers/sensors/cxd5610_gnss.c
+++ b/boards/arm/cxd56xx/drivers/sensors/cxd5610_gnss.c
@@ -1633,7 +1633,7 @@ static int cxd5610_gnss_finalize(struct cxd5610_gnss_dev_s *priv)
   /* Finalize CXD5610 device */
 
   cxd5610_gnss_core_finalize(priv);
-  nxsig_sleep(1);
+  nxsched_sleep(1);
 
   /* Terminate thread */
 
diff --git a/boards/arm/cxd56xx/spresense/src/cxd56_power.c b/boards/arm/cxd56xx/spresense/src/cxd56_power.c
index b52c90165c4..9743d7936ad 100644
--- a/boards/arm/cxd56xx/spresense/src/cxd56_power.c
+++ b/boards/arm/cxd56xx/spresense/src/cxd56_power.c
@@ -236,7 +236,7 @@ int board_power_control(int target, bool en)
 
       if (!g_rtc_enabled && (PMIC_GET_TYPE(target) == PMIC_TYPE_GPO))
         {
-          nxsig_usleep(1);
+          nxsched_usleep(1);
         }
     }
 
@@ -274,7 +274,7 @@ int board_power_control_tristate(int target, int value)
 
       if (!g_rtc_enabled)
         {
-          nxsig_usleep(1);
+          nxsched_usleep(1);
         }
     }
   else if (PMIC_GET_TYPE(target) == CHIP_TYPE_GPIO)
diff --git a/boards/arm/lc823450/lc823450-xgevk/src/lc823450_bt.c b/boards/arm/lc823450/lc823450-xgevk/src/lc823450_bt.c
index 6bf19bb0606..8f28e12f521 100644
--- a/boards/arm/lc823450/lc823450-xgevk/src/lc823450_bt.c
+++ b/boards/arm/lc823450/lc823450-xgevk/src/lc823450_bt.c
@@ -56,9 +56,9 @@ void up_bt_enable(int enable)
   if (enable)
     {
       lc823450_gpio_write(BT_POWER, 0);
-      nxsig_usleep(100 * 1000);
+      nxsched_usleep(100 * 1000);
       lc823450_gpio_write(BT_POWER, 1);
-      nxsig_usleep(100 * 1000);
+      nxsched_usleep(100 * 1000);
     }
   else
     {
diff --git a/boards/arm/lpc17xx_40xx/u-blox-c027/src/lpc17_40_ubxmdm.c b/boards/arm/lpc17xx_40xx/u-blox-c027/src/lpc17_40_ubxmdm.c
index 239d7c71cf2..53503bba2ac 100644
--- a/boards/arm/lpc17xx_40xx/u-blox-c027/src/lpc17_40_ubxmdm.c
+++ b/boards/arm/lpc17xx_40xx/u-blox-c027/src/lpc17_40_ubxmdm.c
@@ -268,7 +268,7 @@ static int lpc17_40_poweron(struct ubxmdm_lower * lower)
 
   /* Min. time for power_on_n being low is 5 ms */
 
-  nxsig_usleep(10 * 1000);
+  nxsched_usleep(10 * 1000);
 
   if (priv->usb_used)
     {
@@ -287,7 +287,7 @@ static int lpc17_40_poweron(struct ubxmdm_lower * lower)
 
   /* Delay to obtain correct voltage on shifters */
 
-  nxsig_usleep(1 * 1000);
+  nxsched_usleep(1 * 1000);
 
   /* UART shifter enabled */
 
@@ -339,7 +339,7 @@ static int lpc17_40_reset(struct ubxmdm_lower * lower)
 
   /* The minimum reset_n low time is 50 ms */
 
-  nxsig_usleep(75 * 1000);
+  nxsched_usleep(75 * 1000);
 
   /* Modem not in reset */
 
diff --git a/boards/arm/nrf52/nrf52840-dk/src/nrf52_highpri.c b/boards/arm/nrf52/nrf52840-dk/src/nrf52_highpri.c
index 0ca7b7c32fa..e58287f08ed 100644
--- a/boards/arm/nrf52/nrf52840-dk/src/nrf52_highpri.c
+++ b/boards/arm/nrf52/nrf52840-dk/src/nrf52_highpri.c
@@ -257,7 +257,7 @@ int highpri_main(int argc, char *argv[])
       /* Flush stdout and wait a bit */
 
       fflush(stdout);
-      nxsig_sleep(1);
+      nxsched_sleep(1);
       seconds++;
 
       /* Sample counts so that they are not volatile.  Missing a count now
diff --git a/boards/arm/nrf52/nrf52840-dk/src/nrf52_sx127x.c b/boards/arm/nrf52/nrf52840-dk/src/nrf52_sx127x.c
index 02e7ee4e191..20d08c7de4a 100644
--- a/boards/arm/nrf52/nrf52840-dk/src/nrf52_sx127x.c
+++ b/boards/arm/nrf52/nrf52840-dk/src/nrf52_sx127x.c
@@ -110,7 +110,7 @@ static void sx127x_chip_reset(void)
 
   /* Wait 1 ms */
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Configure reset as input */
 
@@ -118,7 +118,7 @@ static void sx127x_chip_reset(void)
 
   /* Wait 10 ms */
 
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
 }
 
 /****************************************************************************
diff --git a/boards/arm/s32k3xx/mr-canhubk3/src/s32k3xx_tja1153.c b/boards/arm/s32k3xx/mr-canhubk3/src/s32k3xx_tja1153.c
index ad3680d17ad..cbaa0e68421 100644
--- a/boards/arm/s32k3xx/mr-canhubk3/src/s32k3xx_tja1153.c
+++ b/boards/arm/s32k3xx/mr-canhubk3/src/s32k3xx_tja1153.c
@@ -310,7 +310,7 @@ int s32k3xx_tja1153_initialize(int bus)
 
   /* Sleep for 100 ms to ensure that CAN frames have been transmitted */
 
-  nxsig_usleep(100 * 1000);
+  nxsched_usleep(100 * 1000);
 
   /* TJA1153 must be taken out of STB mode */
 
diff --git a/boards/arm/sam34/sam4s-xplained-pro/src/sam_wdt.c b/boards/arm/sam34/sam4s-xplained-pro/src/sam_wdt.c
index 7be59ac1bd2..738ea59e0d1 100644
--- a/boards/arm/sam34/sam4s-xplained-pro/src/sam_wdt.c
+++ b/boards/arm/sam34/sam4s-xplained-pro/src/sam_wdt.c
@@ -105,10 +105,10 @@ static int wdog_daemon(int argc, char *argv[])
       goto errout_with_dev;
     }
 
-  nxsig_usleep(200);
+  nxsched_usleep(200);
   while (1)
     {
-      nxsig_usleep((CONFIG_WDT_THREAD_INTERVAL)*1000);
+      nxsched_usleep((CONFIG_WDT_THREAD_INTERVAL)*1000);
 
       wdinfo("ping\n");
       ret = file_ioctl(&filestruct, WDIOC_KEEPALIVE, 0);
diff --git a/boards/arm/sama5/sama5d3-xplained/src/sam_bringup.c b/boards/arm/sama5/sama5d3-xplained/src/sam_bringup.c
index a5b95c755dc..691a967f678 100644
--- a/boards/arm/sama5/sama5d3-xplained/src/sam_bringup.c
+++ b/boards/arm/sama5/sama5d3-xplained/src/sam_bringup.c
@@ -166,7 +166,7 @@ int sam_bringup(void)
         {
           /* Wait for mmc block driver to be registered. */
 
-          nxsig_sleep(1);
+          nxsched_sleep(1);
 
           /* Mount the volume on HSMCI0 */
 
diff --git a/boards/arm/samv7/same70-qmtech/src/sam_bringup.c b/boards/arm/samv7/same70-qmtech/src/sam_bringup.c
index b4818e111c9..26472756608 100644
--- a/boards/arm/samv7/same70-qmtech/src/sam_bringup.c
+++ b/boards/arm/samv7/same70-qmtech/src/sam_bringup.c
@@ -175,7 +175,7 @@ int sam_bringup(void)
     {
       if (sam_cardinserted(HSMCI0_SLOTNO))
         {
-          nxsig_usleep(1000 * 1000);
+          nxsched_usleep(1000 * 1000);
 
           /* Mount the volume on HSMCI0 */
 
diff --git a/boards/arm/samv7/same70-xplained/src/sam_bringup.c b/boards/arm/samv7/same70-xplained/src/sam_bringup.c
index cc70d7b8a02..efa70e14b86 100644
--- a/boards/arm/samv7/same70-xplained/src/sam_bringup.c
+++ b/boards/arm/samv7/same70-xplained/src/sam_bringup.c
@@ -236,7 +236,7 @@ int sam_bringup(void)
     {
       if (sam_cardinserted(HSMCI0_SLOTNO))
         {
-          nxsig_usleep(1000 * 1000);
+          nxsched_usleep(1000 * 1000);
 
           /* Mount the volume on HSMCI0 */
 
diff --git a/boards/arm/samv7/samv71-xult/src/sam_bringup.c b/boards/arm/samv7/samv71-xult/src/sam_bringup.c
index 2a4dbffec98..68f5a6f6474 100644
--- a/boards/arm/samv7/samv71-xult/src/sam_bringup.c
+++ b/boards/arm/samv7/samv71-xult/src/sam_bringup.c
@@ -357,7 +357,7 @@ int sam_bringup(void)
     {
       if (sam_cardinserted(HSMCI0_SLOTNO))
         {
-          nxsig_usleep(1000 * 1000);
+          nxsched_usleep(1000 * 1000);
 
           /* Mount the volume on HSMCI0 */
 
diff --git a/boards/arm/stm32/axoloti/src/stm32_extmem.c b/boards/arm/stm32/axoloti/src/stm32_extmem.c
index 984dca3a638..66b789973e0 100644
--- a/boards/arm/stm32/axoloti/src/stm32_extmem.c
+++ b/boards/arm/stm32/axoloti/src/stm32_extmem.c
@@ -237,7 +237,7 @@ int stm32_sdram_initialize(void)
    * power-up).
    */
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Step 5:
    * Set MODE bits to ‘010’ and configure the Target Bank bits (CTB1
diff --git a/boards/arm/stm32/clicker2-stm32/src/stm32_appinit.c b/boards/arm/stm32/clicker2-stm32/src/stm32_appinit.c
index 5ae277a89d4..5d2f5e624e4 100644
--- a/boards/arm/stm32/clicker2-stm32/src/stm32_appinit.c
+++ b/boards/arm/stm32/clicker2-stm32/src/stm32_appinit.c
@@ -96,7 +96,7 @@ int board_app_initialize(uintptr_t arg)
    * bringing up file syslog.
    */
 
-  nxsig_usleep(CONFIG_CLICKER2_STM32_SYSLOG_FILE_DELAY * 1000);
+  nxsched_usleep(CONFIG_CLICKER2_STM32_SYSLOG_FILE_DELAY * 1000);
 
   syslog_channel_t *channel;
   channel = syslog_file_channel(CONFIG_CLICKER2_STM32_SYSLOG_FILE_PATH);
diff --git a/boards/arm/stm32/cloudctrl/src/stm32_relays.c b/boards/arm/stm32/cloudctrl/src/stm32_relays.c
index 25ffa5d1f71..110fa12b042 100644
--- a/boards/arm/stm32/cloudctrl/src/stm32_relays.c
+++ b/boards/arm/stm32/cloudctrl/src/stm32_relays.c
@@ -231,11 +231,11 @@ void relays_onoff(int relays, uint32_t mdelay)
           if (relays_getstat(relays))
             {
               relays_setstat(relays, false);
-              nxsig_usleep(RELAYS_MIN_RESET_TIME * 1000 * 1000);
+              nxsched_usleep(RELAYS_MIN_RESET_TIME * 1000 * 1000);
             }
 
           relays_setstat(relays, true);
-          nxsig_usleep(mdelay * 100 * 1000);
+          nxsched_usleep(mdelay * 100 * 1000);
           relays_setstat(relays, false);
         }
     }
diff --git a/boards/arm/stm32/nucleo-f302r8/src/stm32_highpri.c b/boards/arm/stm32/nucleo-f302r8/src/stm32_highpri.c
index 1cb8b47c875..0d967c00c14 100644
--- a/boards/arm/stm32/nucleo-f302r8/src/stm32_highpri.c
+++ b/boards/arm/stm32/nucleo-f302r8/src/stm32_highpri.c
@@ -490,7 +490,7 @@ int highpri_main(int argc, char *argv[])
 
       adc1->ad_ops->ao_ioctl(adc1, IO_TRIGGER_REG, 0);
 
-      nxsig_usleep(100);
+      nxsched_usleep(100);
 #endif
 
 #ifdef HIGHPRI_HAVE_INJECTED
@@ -498,7 +498,7 @@ int highpri_main(int argc, char *argv[])
 
       adc1->ad_ops->ao_ioctl(adc1, IO_TRIGGER_INJ, 0);
 
-      nxsig_usleep(100);
+      nxsched_usleep(100);
 #endif
       /* Lock global data */
 
@@ -534,7 +534,7 @@ int highpri_main(int argc, char *argv[])
 
       g_highpri.lock = false;
 
-      nxsig_sleep(1);
+      nxsched_sleep(1);
     }
 
 errout:
diff --git a/boards/arm/stm32/nucleo-f334r8/src/stm32_highpri.c b/boards/arm/stm32/nucleo-f334r8/src/stm32_highpri.c
index eaa1bfba2c9..5311cdc5b32 100644
--- a/boards/arm/stm32/nucleo-f334r8/src/stm32_highpri.c
+++ b/boards/arm/stm32/nucleo-f334r8/src/stm32_highpri.c
@@ -532,7 +532,7 @@ int highpri_main(int argc, char *argv[])
 
       adc1->ad_ops->ao_ioctl(adc1, IO_TRIGGER_REG, 0);
 
-      nxsig_usleep(100);
+      nxsched_usleep(100);
 #endif
 
 #ifdef HIGHPRI_HAVE_INJECTED
@@ -540,7 +540,7 @@ int highpri_main(int argc, char *argv[])
 
       adc1->ad_ops->ao_ioctl(adc1, IO_TRIGGER_INJ, 0);
 
-      nxsig_usleep(100);
+      nxsched_usleep(100);
 #endif
       /* Lock global data */
 
@@ -576,7 +576,7 @@ int highpri_main(int argc, char *argv[])
 
       g_highpri.lock = false;
 
-      nxsig_sleep(1);
+      nxsched_sleep(1);
     }
 
 errout:
diff --git a/boards/arm/stm32/nucleo-f334r8/src/stm32_spwm.c b/boards/arm/stm32/nucleo-f334r8/src/stm32_spwm.c
index 83ee36087a2..1bb93258e20 100644
--- a/boards/arm/stm32/nucleo-f334r8/src/stm32_spwm.c
+++ b/boards/arm/stm32/nucleo-f334r8/src/stm32_spwm.c
@@ -1034,7 +1034,7 @@ int spwm_main(int argc, char *argv[])
 
       /* Sleep */
 
-      nxsig_sleep(1);
+      nxsched_sleep(1);
     }
 
 errout:
diff --git a/boards/arm/stm32/photon/src/stm32_wdt.c b/boards/arm/stm32/photon/src/stm32_wdt.c
index 985261072c0..b92a05da161 100644
--- a/boards/arm/stm32/photon/src/stm32_wdt.c
+++ b/boards/arm/stm32/photon/src/stm32_wdt.c
@@ -75,7 +75,7 @@ static int wdog_daemon(int argc, char *argv[])
 
   while (1)
     {
-      nxsig_usleep((CONFIG_PHOTON_WDG_THREAD_INTERVAL)*1000);
+      nxsched_usleep((CONFIG_PHOTON_WDG_THREAD_INTERVAL)*1000);
 
       /* Send keep alive ioctl */
 
diff --git a/boards/arm/stm32/shenzhou/src/stm32_relays.c b/boards/arm/stm32/shenzhou/src/stm32_relays.c
index 21a3ccb4f97..2f9405a3532 100644
--- a/boards/arm/stm32/shenzhou/src/stm32_relays.c
+++ b/boards/arm/stm32/shenzhou/src/stm32_relays.c
@@ -231,11 +231,11 @@ void relays_onoff(int relays, uint32_t mdelay)
           if (relays_getstat(relays))
             {
               relays_setstat(relays, false);
-              nxsig_usleep(RELAYS_MIN_RESET_TIME * 1000 * 1000);
+              nxsched_usleep(RELAYS_MIN_RESET_TIME * 1000 * 1000);
             }
 
           relays_setstat(relays, true);
-          nxsig_usleep(mdelay * 100 * 1000);
+          nxsched_usleep(mdelay * 100 * 1000);
           relays_setstat(relays, false);
         }
     }
diff --git a/boards/arm/stm32/stm32butterfly2/src/stm32_mmcsd.c b/boards/arm/stm32/stm32butterfly2/src/stm32_mmcsd.c
index 8dad288dd11..09724380879 100644
--- a/boards/arm/stm32/stm32butterfly2/src/stm32_mmcsd.c
+++ b/boards/arm/stm32/stm32butterfly2/src/stm32_mmcsd.c
@@ -98,7 +98,7 @@ static void *stm32_cd_thread(void *arg)
            * rest for a millisecond or so.
            */
 
-          nxsig_usleep(1 * 1000);
+          nxsched_usleep(1 * 1000);
           g_chmediaclbk(g_chmediaarg);
         }
     }
diff --git a/boards/arm/stm32/stm32f103-minimum/src/stm32_hyt271.c b/boards/arm/stm32/stm32f103-minimum/src/stm32_hyt271.c
index 00fec100946..38edb047806 100644
--- a/boards/arm/stm32/stm32f103-minimum/src/stm32_hyt271.c
+++ b/boards/arm/stm32/stm32f103-minimum/src/stm32_hyt271.c
@@ -113,7 +113,7 @@ static int stm32_i2c_power_reset(struct hyt271_bus_s *bus)
     }
 
   stm32_gpiowrite(BOARD_HYT271_POWOUT, false);
-  nxsig_usleep(250000);
+  nxsched_usleep(250000);
   stm32_gpiowrite(BOARD_HYT271_POWOUT, true);
 
   while (1)
diff --git a/boards/arm/stm32/stm32f429i-disco/src/stm32_highpri.c b/boards/arm/stm32/stm32f429i-disco/src/stm32_highpri.c
index b7b452882ae..786e1ec9b9d 100644
--- a/boards/arm/stm32/stm32f429i-disco/src/stm32_highpri.c
+++ b/boards/arm/stm32/stm32f429i-disco/src/stm32_highpri.c
@@ -481,7 +481,7 @@ int highpri_main(int argc, char *argv[])
 
       adc1->ad_ops->ao_ioctl(adc1, IO_TRIGGER_REG, 0);
 
-      nxsig_usleep(100);
+      nxsched_usleep(100);
 #endif
 
 #ifdef HIGHPRI_HAVE_INJECTED
@@ -489,7 +489,7 @@ int highpri_main(int argc, char *argv[])
 
       adc1->ad_ops->ao_ioctl(adc1, IO_TRIGGER_INJ, 0);
 
-      nxsig_usleep(100);
+      nxsched_usleep(100);
 #endif
       /* Lock global data */
 
@@ -525,7 +525,7 @@ int highpri_main(int argc, char *argv[])
 
       g_highpri.lock = false;
 
-      nxsig_sleep(1);
+      nxsched_sleep(1);
     }
 
 errout:
diff --git a/boards/arm/stm32/stm32f4discovery/src/stm32_sx127x.c b/boards/arm/stm32/stm32f4discovery/src/stm32_sx127x.c
index f1427472788..3b4bfa2d205 100644
--- a/boards/arm/stm32/stm32f4discovery/src/stm32_sx127x.c
+++ b/boards/arm/stm32/stm32f4discovery/src/stm32_sx127x.c
@@ -113,7 +113,7 @@ static void sx127x_chip_reset(void)
 
   /* Wait 1 ms */
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Configure reset as input */
 
@@ -121,7 +121,7 @@ static void sx127x_chip_reset(void)
 
   /* Wait 10 ms */
 
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
 }
 
 /****************************************************************************
diff --git a/boards/arm/stm32/viewtool-stm32f107/src/stm32_highpri.c b/boards/arm/stm32/viewtool-stm32f107/src/stm32_highpri.c
index c647f70e5ba..b9d97434c77 100644
--- a/boards/arm/stm32/viewtool-stm32f107/src/stm32_highpri.c
+++ b/boards/arm/stm32/viewtool-stm32f107/src/stm32_highpri.c
@@ -225,7 +225,7 @@ int highpri_main(int argc, char *argv[])
       /* Flush stdout and wait a bit */
 
       fflush(stdout);
-      nxsig_sleep(1);
+      nxsched_sleep(1);
       seconds++;
 
       /* Sample counts so that they are not volatile.  Missing a count now
diff --git a/boards/arm/stm32f0l0g0/b-l072z-lrwan1/src/stm32_sx127x.c b/boards/arm/stm32f0l0g0/b-l072z-lrwan1/src/stm32_sx127x.c
index 5ee5ef74536..c09538de891 100644
--- a/boards/arm/stm32f0l0g0/b-l072z-lrwan1/src/stm32_sx127x.c
+++ b/boards/arm/stm32f0l0g0/b-l072z-lrwan1/src/stm32_sx127x.c
@@ -114,7 +114,7 @@ static void sx127x_chip_reset(void)
 
   /* Wait 1 ms */
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Configure reset as input */
 
@@ -122,7 +122,7 @@ static void sx127x_chip_reset(void)
 
   /* Wait 10 ms */
 
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
 }
 
 /****************************************************************************
diff --git a/boards/arm/stm32f0l0g0/nucleo-f091rc/src/stm32_sx127x.c b/boards/arm/stm32f0l0g0/nucleo-f091rc/src/stm32_sx127x.c
index 185d40d4d97..0352392bf60 100644
--- a/boards/arm/stm32f0l0g0/nucleo-f091rc/src/stm32_sx127x.c
+++ b/boards/arm/stm32f0l0g0/nucleo-f091rc/src/stm32_sx127x.c
@@ -112,7 +112,7 @@ static void sx127x_chip_reset(void)
 
   /* Wait 1 ms */
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Configure reset as input */
 
@@ -120,7 +120,7 @@ static void sx127x_chip_reset(void)
 
   /* Wait 10 ms */
 
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
 }
 
 /****************************************************************************
diff --git a/boards/arm/stm32f0l0g0/nucleo-l073rz/src/stm32_sx127x.c b/boards/arm/stm32f0l0g0/nucleo-l073rz/src/stm32_sx127x.c
index 4de2e91098c..afc807ce3d5 100644
--- a/boards/arm/stm32f0l0g0/nucleo-l073rz/src/stm32_sx127x.c
+++ b/boards/arm/stm32f0l0g0/nucleo-l073rz/src/stm32_sx127x.c
@@ -112,7 +112,7 @@ static void sx127x_chip_reset(void)
 
   /* Wait 1 ms */
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Configure reset as input */
 
@@ -120,7 +120,7 @@ static void sx127x_chip_reset(void)
 
   /* Wait 10 ms */
 
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
 }
 
 /****************************************************************************
diff --git a/boards/arm/stm32l4/b-l475e-iot01a/src/stm32_spirit.c b/boards/arm/stm32l4/b-l475e-iot01a/src/stm32_spirit.c
index 0dfcaf72337..6e2ca3cab2d 100644
--- a/boards/arm/stm32l4/b-l475e-iot01a/src/stm32_spirit.c
+++ b/boards/arm/stm32l4/b-l475e-iot01a/src/stm32_spirit.c
@@ -135,7 +135,7 @@ static int stm32l4_reset(const struct spirit_lower_s *lower)
 
   /* Wait minimum 1.5 ms to allow Spirit a proper boot-up sequence */
 
-  nxsig_usleep(1500);
+  nxsched_usleep(1500);
   return OK;
 }
 
diff --git a/boards/arm/stm32l4/nucleo-l432kc/src/stm32_dac_wgen.c b/boards/arm/stm32l4/nucleo-l432kc/src/stm32_dac_wgen.c
index 87f731fd24d..0b19d27821a 100644
--- a/boards/arm/stm32l4/nucleo-l432kc/src/stm32_dac_wgen.c
+++ b/boards/arm/stm32l4/nucleo-l432kc/src/stm32_dac_wgen.c
@@ -277,7 +277,7 @@ int dac_wgen_main(int argc, char *argv[])
 
       /* Sleep */
 
-      nxsig_sleep(1);
+      nxsched_sleep(1);
     }
 
 errout:
diff --git a/boards/arm/stm32l4/nucleo-l432kc/src/stm32_spwm.c b/boards/arm/stm32l4/nucleo-l432kc/src/stm32_spwm.c
index def0b4cc547..63bcbcb47b9 100644
--- a/boards/arm/stm32l4/nucleo-l432kc/src/stm32_spwm.c
+++ b/boards/arm/stm32l4/nucleo-l432kc/src/stm32_spwm.c
@@ -630,7 +630,7 @@ int spwm_main(int argc, char *argv[])
 
       /* Sleep */
 
-      nxsig_sleep(1);
+      nxsched_sleep(1);
     }
 
 errout:
diff --git a/boards/sparc/bm3803/xx3803/src/bm3803_wdt.c b/boards/sparc/bm3803/xx3803/src/bm3803_wdt.c
index 3ae4b44b406..729fb6bade6 100644
--- a/boards/sparc/bm3803/xx3803/src/bm3803_wdt.c
+++ b/boards/sparc/bm3803/xx3803/src/bm3803_wdt.c
@@ -76,7 +76,7 @@ static int wdog_daemon(int argc, char *argv[])
 
   while (1)
     {
-      nxsig_usleep((CONFIG_XX3803_WDG_THREAD_INTERVAL)*1000);
+      nxsched_usleep((CONFIG_XX3803_WDG_THREAD_INTERVAL)*1000);
 
       /* Send keep alive ioctl */
 
diff --git a/boards/sparc/s698pm/s698pm-dkit/src/s698pm_wdt.c b/boards/sparc/s698pm/s698pm-dkit/src/s698pm_wdt.c
index 9bfe479aef0..5d14a3087b2 100644
--- a/boards/sparc/s698pm/s698pm-dkit/src/s698pm_wdt.c
+++ b/boards/sparc/s698pm/s698pm-dkit/src/s698pm_wdt.c
@@ -76,7 +76,7 @@ static int wdog_daemon(int argc, char *argv[])
 
   while (1)
     {
-      nxsig_usleep((CONFIG_S698PM_DKIT_WDG_THREAD_INTERVAL)*1000);
+      nxsched_usleep((CONFIG_S698PM_DKIT_WDG_THREAD_INTERVAL)*1000);
 
       /* Send keep alive ioctl */
 
diff --git a/boards/xtensa/esp32/lilygo_tbeam_lora_gps/src/esp32_sx127x.c b/boards/xtensa/esp32/lilygo_tbeam_lora_gps/src/esp32_sx127x.c
index 6c8f09993f7..4bea04c860a 100644
--- a/boards/xtensa/esp32/lilygo_tbeam_lora_gps/src/esp32_sx127x.c
+++ b/boards/xtensa/esp32/lilygo_tbeam_lora_gps/src/esp32_sx127x.c
@@ -129,7 +129,7 @@ static void sx127x_chip_reset(void)
 
   /* Wait 1 ms */
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Set pin to high */
 
@@ -137,7 +137,7 @@ static void sx127x_chip_reset(void)
 
   /* Wait 10 ms */
 
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
 }
 
 /****************************************************************************
diff --git a/boards/xtensa/esp32/ttgo_lora_esp32/src/esp32_sx127x.c b/boards/xtensa/esp32/ttgo_lora_esp32/src/esp32_sx127x.c
index 9d6c3950408..f28c664d479 100644
--- a/boards/xtensa/esp32/ttgo_lora_esp32/src/esp32_sx127x.c
+++ b/boards/xtensa/esp32/ttgo_lora_esp32/src/esp32_sx127x.c
@@ -129,7 +129,7 @@ static void sx127x_chip_reset(void)
 
   /* Wait 1 ms */
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Set pin to high */
 
@@ -137,7 +137,7 @@ static void sx127x_chip_reset(void)
 
   /* Wait 10 ms */
 
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
 }
 
 /****************************************************************************
diff --git a/boards/xtensa/esp32s3/esp32s3-box/src/esp32s3_board_lcd_ili9342c.c b/boards/xtensa/esp32s3/esp32s3-box/src/esp32s3_board_lcd_ili9342c.c
index 4ac1be322ec..feb41a01a3e 100644
--- a/boards/xtensa/esp32s3/esp32s3-box/src/esp32s3_board_lcd_ili9342c.c
+++ b/boards/xtensa/esp32s3/esp32s3-box/src/esp32s3_board_lcd_ili9342c.c
@@ -494,11 +494,11 @@ static struct ili9341_lcd_s *esp32s3_initializa_ili9342c(int spi_port)
 
   /* Reset LCD */
 
-  nxsig_usleep(10 * 1000);
+  nxsched_usleep(10 * 1000);
   esp32s3_gpiowrite(DISPLAY_RST, true);
-  nxsig_usleep(10 * 1000);
+  nxsched_usleep(10 * 1000);
   esp32s3_gpiowrite(DISPLAY_RST, false);
-  nxsig_usleep(50 * 1000);
+  nxsched_usleep(50 * 1000);
 
   /* Turn on LCD backlight */
 
diff --git a/boards/xtensa/esp32s3/esp32s3-box/src/esp32s3_board_lcd_st7789.c b/boards/xtensa/esp32s3/esp32s3-box/src/esp32s3_board_lcd_st7789.c
index 26d13278a1b..4326144b78a 100644
--- a/boards/xtensa/esp32s3/esp32s3-box/src/esp32s3_board_lcd_st7789.c
+++ b/boards/xtensa/esp32s3/esp32s3-box/src/esp32s3_board_lcd_st7789.c
@@ -85,9 +85,9 @@ int board_lcd_initialize(void)
   /* Reset LCD */
 
   esp32s3_gpiowrite(DISPLAY_RST, false);
-  nxsig_usleep(10 * 1000);
+  nxsched_usleep(10 * 1000);
   esp32s3_gpiowrite(DISPLAY_RST, true);
-  nxsig_usleep(10 * 1000);
+  nxsched_usleep(10 * 1000);
 
   /* Turn on LCD backlight */
 
diff --git a/boards/xtensa/esp32s3/esp32s3-devkit/src/esp32s3_st7735.c b/boards/xtensa/esp32s3/esp32s3-devkit/src/esp32s3_st7735.c
index 140a3b74b4d..0a1f823538e 100644
--- a/boards/xtensa/esp32s3/esp32s3-devkit/src/esp32s3_st7735.c
+++ b/boards/xtensa/esp32s3/esp32s3-devkit/src/esp32s3_st7735.c
@@ -87,9 +87,9 @@ int board_lcd_initialize(void)
 
   esp32s3_configgpio(GPIO_LCD_RST, OUTPUT);
   esp32s3_gpiowrite(GPIO_LCD_RST, false);
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
   esp32s3_gpiowrite(GPIO_LCD_RST, true);
-  nxsig_usleep(100000);
+  nxsched_usleep(100000);
 
   return OK;
 }
diff --git a/boards/xtensa/esp32s3/esp32s3-lcd-ev/src/esp32s3_lcd.c b/boards/xtensa/esp32s3/esp32s3-lcd-ev/src/esp32s3_lcd.c
index b6bb5d09dea..e402dc83ef7 100644
--- a/boards/xtensa/esp32s3/esp32s3-lcd-ev/src/esp32s3_lcd.c
+++ b/boards/xtensa/esp32s3/esp32s3-lcd-ev/src/esp32s3_lcd.c
@@ -631,7 +631,7 @@ static void lcd_configure_display(void)
 
   /* Wait until LCD is ready */
 
-  nxsig_usleep(120 * 1000);
+  nxsched_usleep(120 * 1000);
 
   /* Display on */
 
@@ -639,7 +639,7 @@ static void lcd_configure_display(void)
 
   /* Wait until LCD is on */
 
-  nxsig_usleep(20 * 1000);
+  nxsched_usleep(20 * 1000);
 }
 
 /****************************************************************************
diff --git a/boards/z80/ez80/z20x/src/w25_main.c b/boards/z80/ez80/z20x/src/w25_main.c
index e54565c55d4..277c43aa3f7 100644
--- a/boards/z80/ez80/z20x/src/w25_main.c
+++ b/boards/z80/ez80/z20x/src/w25_main.c
@@ -690,7 +690,7 @@ static int w25_wait_keypress(FAR char *keyset, int nseconds)
 
           /* Delay 50 Milliseconds  */
 
-          nxsig_usleep(50 * 1000);
+          nxsched_usleep(50 * 1000);
 
           /* Output a dot to stdout every 10 * 50 = 500 milliseconds */
 
diff --git a/drivers/analog/ads1255.c b/drivers/analog/ads1255.c
index 1293609ff01..d56305a6d19 100644
--- a/drivers/analog/ads1255.c
+++ b/drivers/analog/ads1255.c
@@ -278,7 +278,7 @@ static void adc_reset(FAR struct adc_dev_s *dev)
   spi = priv->spi;
 
   adc_lock(spi);
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   SPI_SELECT(spi, priv->devno, true);
   SPI_SEND(spi, ADS125X_WREG + 0x03);  /* WRITE SPS REG */
@@ -329,7 +329,7 @@ static int adc_setup(FAR struct adc_dev_s *dev)
       SPI_SEND(spi, priv->mux[0]);
       SPI_SEND(spi, priv->pga);            /* REG2 ADCON PGA=2 */
       SPI_SEND(spi, getspsreg(priv->sps));
-      nxsig_usleep(1000);
+      nxsched_usleep(1000);
       SPI_SEND(spi, ADS125X_SELFCAL);
       SPI_SELECT(spi, priv->devno, false);
 
diff --git a/drivers/analog/dac.c b/drivers/analog/dac.c
index 2b3291c4409..27196505c89 100644
--- a/drivers/analog/dac.c
+++ b/drivers/analog/dac.c
@@ -183,7 +183,7 @@ static int dac_close(FAR struct file *filep)
 
           while (dev->ad_xmit.af_head != dev->ad_xmit.af_tail)
             {
-               nxsig_usleep(HALF_SECOND_USEC);
+               nxsched_usleep(HALF_SECOND_USEC);
             }
 
           /* Free the IRQ and disable the DAC device */
diff --git a/drivers/audio/audio_fake.c b/drivers/audio/audio_fake.c
index d6a1f830e13..e98b875940d 100644
--- a/drivers/audio/audio_fake.c
+++ b/drivers/audio/audio_fake.c
@@ -436,7 +436,7 @@ static int audio_fake_process_buffer(FAR struct audio_lowerhalf_s *dev,
 
   sleep_time = frame_time - diff_time;
 
-  nxsig_usleep(sleep_time);
+  nxsched_usleep(sleep_time);
 
   ret = OK;
 
diff --git a/drivers/audio/audio_null.c b/drivers/audio/audio_null.c
index 83a4633986c..346a79ac5cf 100644
--- a/drivers/audio/audio_null.c
+++ b/drivers/audio/audio_null.c
@@ -175,7 +175,7 @@ static int null_sleep(FAR struct audio_lowerhalf_s *dev,
   uint64_t sleep_time;
 
   sleep_time = USEC_PER_SEC * (uint64_t)apb->nbytes / priv->scaler;
-  nxsig_usleep(sleep_time);
+  nxsched_usleep(sleep_time);
 #ifdef CONFIG_AUDIO_MULTI_SESSION
   priv->dev.upper(priv->dev.priv, AUDIO_CALLBACK_DEQUEUE,
                   apb, OK, NULL);
diff --git a/drivers/audio/vs1053.c b/drivers/audio/vs1053.c
index e9f2d31d058..38a2c23fa95 100644
--- a/drivers/audio/vs1053.c
+++ b/drivers/audio/vs1053.c
@@ -336,7 +336,7 @@ static void vs1053_writereg(FAR struct vs1053_struct_s *dev,
 
   /* Short delay after a write for VS1053 processing time */
 
-  nxsig_usleep(10);
+  nxsched_usleep(10);
 }
 
 /****************************************************************************
@@ -412,7 +412,7 @@ static int vs1053_setfrequency(FAR struct vs1053_struct_s *dev,
   timeout = 200;
   while (!dev->hw_lower->read_dreq(dev->hw_lower) && timeout)
     {
-      nxsig_usleep(1000);
+      nxsched_usleep(1000);
       timeout--;
     }
 
@@ -925,9 +925,9 @@ static int vs1053_hardreset(FAR struct vs1053_struct_s *dev)
 {
   dev->hw_lower->disable(dev->hw_lower);   /* Disable the DREQ interrupt */
   dev->hw_lower->reset(dev->hw_lower, false);
-  nxsig_usleep(10);
+  nxsched_usleep(10);
   dev->hw_lower->reset(dev->hw_lower, true);
-  nxsig_usleep(VS1053_RST_USECS);
+  nxsched_usleep(VS1053_RST_USECS);
   vs1053_setfrequency(dev, CONFIG_VS1053_XTALI);  /* Slow speed at first */
 
   return OK;
@@ -1316,7 +1316,7 @@ static void *vs1053_workerthread(pthread_addr_t pvarg)
   timeout = 200;
   while (!dev->hw_lower->read_dreq(dev->hw_lower) && timeout)
     {
-      nxsig_usleep(100);
+      nxsched_usleep(100);
       timeout--;
     }
 
@@ -1352,7 +1352,7 @@ static void *vs1053_workerthread(pthread_addr_t pvarg)
           /* The ISR has requested more data */
 
           case AUDIO_MSG_DATA_REQUEST:
-            nxsig_usleep(500);
+            nxsched_usleep(500);
             vs1053_feeddata(dev);   /* Feed more data to the VS1053 FIFO */
             break;
 
@@ -1362,7 +1362,7 @@ static void *vs1053_workerthread(pthread_addr_t pvarg)
           case AUDIO_MSG_STOP:
             if (!dev->hw_lower->read_dreq(dev->hw_lower))
               {
-                nxsig_usleep(300);
+                nxsched_usleep(300);
               }
 
             /* Send CANCEL message to VS1053 */
diff --git a/drivers/audio/wm8904.c b/drivers/audio/wm8904.c
index 51d43977c40..9379f584bce 100644
--- a/drivers/audio/wm8904.c
+++ b/drivers/audio/wm8904.c
@@ -900,7 +900,7 @@ static void wm8904_setbitrate(FAR struct wm8904_dev_s *priv)
   retries = 5;
   do
     {
-      nxsig_usleep(5 * 5000);
+      nxsched_usleep(5 * 5000);
     }
   while (priv->locked == false && --retries > 0);
 
@@ -923,7 +923,7 @@ static void wm8904_setbitrate(FAR struct wm8904_dev_s *priv)
   retries = 5;
   do
     {
-       nxsig_usleep(5 * 5000);
+       nxsched_usleep(5 * 5000);
     }
   while ((wm8904_readreg(priv, WM8904_INT_STATUS) &
          WM8904_FLL_LOCK_INT) != 0 ||
diff --git a/drivers/can/can.c b/drivers/can/can.c
index d2c87067bf8..f342d20b316 100644
--- a/drivers/can/can.c
+++ b/drivers/can/can.c
@@ -347,14 +347,14 @@ static int can_close(FAR struct file *filep)
 
   while (!TX_EMPTY(&dev->cd_sender))
     {
-      nxsig_usleep(HALF_SECOND_USEC);
+      nxsched_usleep(HALF_SECOND_USEC);
     }
 
   /* And wait for the hardware sender to drain */
 
   while (!dev_txempty(dev))
     {
-      nxsig_usleep(HALF_SECOND_USEC);
+      nxsched_usleep(HALF_SECOND_USEC);
     }
 
   /* Free the IRQ and disable the CAN device */
diff --git a/drivers/can/mcp2515.c b/drivers/can/mcp2515.c
index 22f42df1b00..242fb2a358a 100644
--- a/drivers/can/mcp2515.c
+++ b/drivers/can/mcp2515.c
@@ -1210,7 +1210,7 @@ static void mcp2515_reset_lowlevel(FAR struct mcp2515_can_s *priv)
 
   /* Wait 1ms to let MCP2515 restart */
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Make sure that all buffers are released. */
 
@@ -2457,7 +2457,7 @@ static int mcp2515_hw_initialize(struct mcp2515_can_s *priv)
   regval = (regval & ~CANCTRL_REQOP_MASK) | (CANCTRL_REQOP_NORMAL);
   mcp2515_writeregs(priv, MCP2515_CANCTRL, &regval, 1);
 
-  nxsig_usleep(100);
+  nxsched_usleep(100);
 
   /* Read the CANINTF */
 
diff --git a/drivers/contactless/mfrc522.c b/drivers/contactless/mfrc522.c
index b1018cfe46c..c4385891812 100644
--- a/drivers/contactless/mfrc522.c
+++ b/drivers/contactless/mfrc522.c
@@ -1098,7 +1098,7 @@ void mfrc522_softreset(FAR struct mfrc522_dev_s *dev)
 
   /* Wait the internal state machine to initialize */
 
-  nxsig_usleep(50000);
+  nxsched_usleep(50000);
 
   /* Wait for the PowerDown bit in COMMAND_REG to be cleared */
 
@@ -1424,7 +1424,7 @@ static int mfrc522_open(FAR struct file *filep)
 
   mfrc522_configspi(dev->spi);
 
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
 
   mfrc522_getfwversion(dev);
 
diff --git a/drivers/contactless/pn532.c b/drivers/contactless/pn532.c
index ca0712570d5..620c480ca16 100644
--- a/drivers/contactless/pn532.c
+++ b/drivers/contactless/pn532.c
@@ -310,7 +310,7 @@ static int pn532_wait_rx_ready(FAR struct pn532_dev_s *dev, int timeout)
           return -ETIMEDOUT;
         }
 
-      nxsig_usleep(1000);
+      nxsched_usleep(1000);
     }
 
   dev->state = PN532_STATE_DATA_READY;
@@ -340,7 +340,7 @@ static void pn532_writecommand(FAR struct pn532_dev_s *dev, uint8_t cmd)
 
   pn532_lock(dev->spi);
   pn532_select(dev);
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
 
   SPI_SEND(dev->spi, PN532_SPI_DATAWRITE);
   SPI_SNDBLOCK(dev->spi, f, FRAME_SIZE(f));
@@ -449,7 +449,7 @@ int pn532_write_frame(FAR struct pn532_dev_s *dev, FAR struct pn532_frame *f)
 
   pn532_lock(dev->spi);
   pn532_select(dev);
-  nxsig_usleep(2000);
+  nxsched_usleep(2000);
 
   SPI_SEND(dev->spi, PN532_SPI_DATAWRITE);
   SPI_SNDBLOCK(dev->spi, f, FRAME_SIZE(f));
@@ -862,7 +862,7 @@ static int _open(FAR struct file *filep)
   pn532_configspi(dev->spi);
 
   dev->config->reset(1);
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
 
   pn532_sam_config(dev, NULL);
   pn532_get_fw_version(dev, NULL);
diff --git a/drivers/crypto/pnt/sm_timer.c b/drivers/crypto/pnt/sm_timer.c
index 588a5f63299..a0c7f5104c4 100644
--- a/drivers/crypto/pnt/sm_timer.c
+++ b/drivers/crypto/pnt/sm_timer.c
@@ -36,5 +36,5 @@
 
 void sm_sleep(uint32_t msec)
 {
-  nxsig_usleep(1000 * msec);
+  nxsched_usleep(1000 * msec);
 }
diff --git a/drivers/eeprom/spi_xx25xx.c b/drivers/eeprom/spi_xx25xx.c
index 49a53e58ac9..48c754f65df 100644
--- a/drivers/eeprom/spi_xx25xx.c
+++ b/drivers/eeprom/spi_xx25xx.c
@@ -404,7 +404,7 @@ static void ee25xx_waitwritecomplete(struct ee25xx_dev_s *priv)
 
       if ((status & EE25XX_SR_WIP) != 0)
         {
-          nxsig_usleep(1000);
+          nxsched_usleep(1000);
         }
     }
   while ((status & EE25XX_SR_WIP) != 0);
diff --git a/drivers/input/cypress_mbr3108.c b/drivers/input/cypress_mbr3108.c
index 3832b718a32..4acf75db2d9 100644
--- a/drivers/input/cypress_mbr3108.c
+++ b/drivers/input/cypress_mbr3108.c
@@ -403,7 +403,7 @@ static int mbr3108_save_check_crc(FAR struct mbr3108_dev_s *dev)
       return ret;
     }
 
-  nxsig_usleep(MBR3108_CMD_MSECS_CHECK_CONFIG_CRC * 1000);
+  nxsched_usleep(MBR3108_CMD_MSECS_CHECK_CONFIG_CRC * 1000);
 
   ret = mbr3108_check_cmd_status(dev);
   if (ret != 0)
@@ -427,7 +427,7 @@ static int mbr3108_software_reset(FAR struct mbr3108_dev_s *dev)
       return ret;
     }
 
-  nxsig_usleep(MBR3108_CMD_MSECS_SOFTWARE_RESET * 1000);
+  nxsched_usleep(MBR3108_CMD_MSECS_SOFTWARE_RESET * 1000);
 
   ret = mbr3108_check_cmd_status(dev);
   if (ret != 0)
@@ -472,7 +472,7 @@ static int mbr3108_clear_latched(FAR struct mbr3108_dev_s *dev)
       return ret;
     }
 
-  nxsig_usleep(MBR3108_CMD_MSECS_CLEAR_LATCHED * 1000);
+  nxsched_usleep(MBR3108_CMD_MSECS_CLEAR_LATCHED * 1000);
 
   ret = mbr3108_check_cmd_status(dev);
   if (ret != 0)
@@ -888,7 +888,7 @@ static int mbr3108_open(FAR struct file *filep)
 
       /* Let chip to power up before probing */
 
-      nxsig_usleep(100 * 1000);
+      nxsched_usleep(100 * 1000);
 
       /* Check that device exists on I2C. */
 
diff --git a/drivers/input/gt9xx.c b/drivers/input/gt9xx.c
index 3c55103b830..af0eaff8708 100644
--- a/drivers/input/gt9xx.c
+++ b/drivers/input/gt9xx.c
@@ -639,7 +639,7 @@ static int gt9xx_open(FAR struct file *filep)
 
       /* Let Touch Panel power up before probing */
 
-      nxsig_usleep(100 * 1000);
+      nxsched_usleep(100 * 1000);
 
       /* Check that Touch Panel exists on I2C */
 
diff --git a/drivers/input/mxt.c b/drivers/input/mxt.c
index 80f8173e8f8..020ae1a4afe 100644
--- a/drivers/input/mxt.c
+++ b/drivers/input/mxt.c
@@ -1742,7 +1742,7 @@ static int mxt_hwinitialize(FAR struct mxt_dev_s *priv)
       goto errout_with_objtab;
     }
 
-  nxsig_usleep(MXT_RESET_TIME);
+  nxsched_usleep(MXT_RESET_TIME);
 
   /* Update matrix size in the info structure */
 
diff --git a/drivers/input/nunchuck.c b/drivers/input/nunchuck.c
index 0888e54f460..1e8f562f836 100644
--- a/drivers/input/nunchuck.c
+++ b/drivers/input/nunchuck.c
@@ -198,7 +198,7 @@ static int nunchuck_sample(FAR struct nunchuck_dev_s *priv,
 
       /* Delay 20ms */
 
-      nxsig_usleep(20 * 1000);
+      nxsched_usleep(20 * 1000);
 
       initialized = true;
     }
@@ -210,7 +210,7 @@ static int nunchuck_sample(FAR struct nunchuck_dev_s *priv,
 
   /* Wait */
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Read data */
 
@@ -218,35 +218,35 @@ static int nunchuck_sample(FAR struct nunchuck_dev_s *priv,
 
   /* Wait */
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Wait */
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   nunchuck_i2c_read(priv, &data[1], 1);
 
   /* Wait */
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   nunchuck_i2c_read(priv, &data[2], 1);
 
   /* Wait */
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   nunchuck_i2c_read(priv, &data[3], 1);
 
   /* Wait */
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   nunchuck_i2c_read(priv, &data[4], 1);
 
   /* Wait */
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   nunchuck_i2c_read(priv, &data[5], 1);
 
diff --git a/drivers/input/stmpe811_adc.c b/drivers/input/stmpe811_adc.c
index 84769959f91..d0735d48112 100644
--- a/drivers/input/stmpe811_adc.c
+++ b/drivers/input/stmpe811_adc.c
@@ -226,12 +226,12 @@ uint16_t stmpe811_adcread(STMPE811_HANDLE handle, int pin)
   for (i = 0; i < 3; i++)
     {
       /* The worst case ADC conversion time is (nominally) 56.4 uS. The
-       * following nxsig_usleep() looks nice but in reality, nxsig_usleep()
-       * normal does not have that kind of precision (it will probably end
-       * up waiting 10 MS).
+       * following nxsched_usleep() looks nice but in reality,
+       * nxsched_usleep() normal does not have that kind of precision
+       * (it will probably end up waiting 10 MS).
        */
 
-      nxsig_usleep(57);
+      nxsched_usleep(57);
 
       /* Check if the conversion is complete */
 
diff --git a/drivers/input/stmpe811_base.c b/drivers/input/stmpe811_base.c
index c3ceae74bf7..aa4b3e1a60a 100644
--- a/drivers/input/stmpe811_base.c
+++ b/drivers/input/stmpe811_base.c
@@ -224,7 +224,7 @@ static void stmpe811_reset(FAR struct stmpe811_dev_s *priv)
 
   /* Wait a bit */
 
-  nxsig_usleep(20 * 1000);
+  nxsched_usleep(20 * 1000);
 
   /* Then power on again.  All registers will be in their reset state. */
 
diff --git a/drivers/input/tsc2007.c b/drivers/input/tsc2007.c
index c4546083121..c55738692b2 100644
--- a/drivers/input/tsc2007.c
+++ b/drivers/input/tsc2007.c
@@ -477,7 +477,7 @@ static int tsc2007_transfer(FAR struct tsc2007_dev_s *priv, uint8_t cmd)
    *  least 10ms before attempting to read data from the TSC2007...
    */
 
-  nxsig_usleep(10 * 1000);
+  nxsched_usleep(10 * 1000);
 
   /* "Data access begins with the master issuing a START condition followed
    *  by the address byte ... with R/W = 1.
diff --git a/drivers/lcd/ft80x.c b/drivers/lcd/ft80x.c
index ede8b273aa9..98a8efd7f01 100644
--- a/drivers/lcd/ft80x.c
+++ b/drivers/lcd/ft80x.c
@@ -205,7 +205,7 @@ static int ft80x_fade(FAR struct ft80x_dev_s *priv,
     {
       /* Wait for FADE_STEP_MSEC msec (or whatever we get) */
 
-      nxsig_usleep(FADE_STEP_MSEC * 1000);
+      nxsched_usleep(FADE_STEP_MSEC * 1000);
 
       /* Get the elapsed time */
 
diff --git a/drivers/lcd/pcf8574_lcd_backpack.c b/drivers/lcd/pcf8574_lcd_backpack.c
index 6260f0909e4..780c370b89f 100644
--- a/drivers/lcd/pcf8574_lcd_backpack.c
+++ b/drivers/lcd/pcf8574_lcd_backpack.c
@@ -535,7 +535,7 @@ static void lcd_init(FAR struct pcf8574_lcd_dev_s *priv)
 {
   /* Wait for more than 15 ms after Vcc for the LCD to stabilize */
 
-  nxsig_usleep(50000);
+  nxsched_usleep(50000);
 
   /* Perform the init sequence.  This sequence of commands is constructed so
    * that it will get the device into nybble mode irrespective of what state
@@ -548,24 +548,24 @@ static void lcd_init(FAR struct pcf8574_lcd_dev_s *priv)
   /* Send Command 0x30, set 8-bit mode, and wait > 4.1 ms */
 
   latch_nybble(priv, 0x30 >> 4, false);
-  nxsig_usleep(5000);
+  nxsched_usleep(5000);
 
   /* Send Command 0x30, set 8-bit mode, and wait > 100 us */
 
   latch_nybble(priv, 0x30 >> 4, false);
-  nxsig_usleep(5000);
+  nxsched_usleep(5000);
 
   /* Send Command 0x30, set 8-bit mode */
 
   latch_nybble(priv, 0x30 >> 4, false);
-  nxsig_usleep(200);
+  nxsched_usleep(200);
 
   /* now Function set: Set interface to be 4 bits long (only 1 cycle write
    * for the first time).
    */
 
   latch_nybble(priv, 0x20 >> 4, false);
-  nxsig_usleep(5000);
+  nxsched_usleep(5000);
 
   /* Function set: DL=0;Interface is 4 bits, N=1 (2 Lines), F=0 (5x8 dots
    * font)
diff --git a/drivers/lcd/ssd1306_base.c b/drivers/lcd/ssd1306_base.c
index 6b616badf9a..841b613b971 100644
--- a/drivers/lcd/ssd1306_base.c
+++ b/drivers/lcd/ssd1306_base.c
@@ -914,7 +914,7 @@ static int ssd1306_configuredisplay(struct ssd1306_dev_s *priv)
 
   /* Configure OLED SPI or I/O, must be delayed 1-10ms */
 
-  nxsig_usleep(5000);
+  nxsched_usleep(5000);
 
   /* Configure the device */
 
@@ -1310,7 +1310,7 @@ static int ssd1306_configuredisplay(struct ssd1306_dev_s *priv)
 
   ssd1306_select(priv, false);
 
-  nxsig_usleep(100000);
+  nxsched_usleep(100000);
 
   priv->is_conf = true;
   return OK;
diff --git a/drivers/lcd/ssd1680.c b/drivers/lcd/ssd1680.c
index 73a77482309..10865bc918b 100644
--- a/drivers/lcd/ssd1680.c
+++ b/drivers/lcd/ssd1680.c
@@ -457,7 +457,7 @@ static void ssd1680_reset(struct ssd1680_dev_s *priv)
     {
       lcdinfo("Hardware reset\n");
       priv->board_priv->set_rst(false);
-      nxsig_usleep(10);
+      nxsched_usleep(10);
       priv->board_priv->set_rst(true);
     }
   else
@@ -511,7 +511,7 @@ static int ssd1680_setpower(FAR struct lcd_dev_s *dev, int power)
 
           lcdinfo("Set Pwr Ctrl Linepower ON\n");
           priv->board_priv->set_vcc(true);
-          nxsig_usleep(10000);
+          nxsched_usleep(10000);
         }
       else
         {
@@ -934,12 +934,12 @@ static int ssd1680_busy_wait(FAR struct ssd1680_dev_s *priv)
     {
       while (priv->board_priv->check_busy() && max_wait_time-- > 0)
         {
-          nxsig_usleep(1000);
+          nxsched_usleep(1000);
         }
     }
   else
     {
-      nxsig_usleep(max_wait_time * 1000);
+      nxsched_usleep(max_wait_time * 1000);
     }
 
   if (max_wait_time == 0)
diff --git a/drivers/lcd/st7032.c b/drivers/lcd/st7032.c
index 95839b26085..1f8f6626885 100644
--- a/drivers/lcd/st7032.c
+++ b/drivers/lcd/st7032.c
@@ -154,7 +154,7 @@ static inline void st7032_write_inst(FAR struct st7032_dev_s *priv,
 
   /* Delay 30us */
 
-  nxsig_usleep(30);
+  nxsched_usleep(30);
 }
 
 /****************************************************************************
@@ -195,7 +195,7 @@ static inline void st7032_write_data(FAR struct st7032_dev_s *priv,
 
   /* Delay 30us */
 
-  nxsig_usleep(30);
+  nxsched_usleep(30);
 }
 
 static inline void st7032_setcontrast(FAR struct st7032_dev_s *priv,
diff --git a/drivers/leds/ncp5623c.c b/drivers/leds/ncp5623c.c
index 1d8c02c62c4..c6217b96519 100644
--- a/drivers/leds/ncp5623c.c
+++ b/drivers/leds/ncp5623c.c
@@ -159,7 +159,7 @@ static int ncp5623c_open(FAR struct file *filep)
 
   /* Let the chip settle a bit */
 
-  nxsig_usleep(1);
+  nxsched_usleep(1);
   return OK;
 }
 
diff --git a/drivers/leds/pca9635pw.c b/drivers/leds/pca9635pw.c
index 1e1725b280e..de0c176a443 100644
--- a/drivers/leds/pca9635pw.c
+++ b/drivers/leds/pca9635pw.c
@@ -203,7 +203,7 @@ static int pca9635pw_open(FAR struct file *filep)
    * was left.
    */
 
-  nxsig_usleep(500);
+  nxsched_usleep(500);
 
   /* Turn all led drivers to mode 2 in which the led brightness is controlled
    * by the individual pwm registers.
diff --git a/drivers/misc/optee_rpc.c b/drivers/misc/optee_rpc.c
index d0047326fb0..e3e8c6e39a5 100644
--- a/drivers/misc/optee_rpc.c
+++ b/drivers/misc/optee_rpc.c
@@ -119,13 +119,7 @@ static void optee_rpc_cmd_suspend(FAR struct optee_msg_arg *arg)
 
   if (usec_to_wait)
     {
-      int ret = nxsig_usleep(usec_to_wait);
-
-      if (ret < 0 && ret != -EINTR)
-        {
-            arg->ret = TEE_ERROR_GENERIC;
-            return;
-        }
+      nxsched_usleep(usec_to_wait);
     }
 
   arg->ret = TEE_SUCCESS;
diff --git a/drivers/mmcsd/Kconfig b/drivers/mmcsd/Kconfig
index e550fdcbe64..648c41adde9 100644
--- a/drivers/mmcsd/Kconfig
+++ b/drivers/mmcsd/Kconfig
@@ -181,7 +181,7 @@ config MMCSD_CHECK_READY_STATUS_WITHOUT_SLEEP
 	bool "No sleep in ready-check function."
 	default n
 	---help---
-		Since nxsig_usleep returns at the tick after the next tick, when
+		Since nxsched_usleep returns at the tick after the next tick, when
 		CONFIG_USEC_PER_TICK is big, the real sleep time is much more than
 		desired in mmcsd_transferready(). As a result, write speed is
 		affected seriously.
diff --git a/drivers/mmcsd/mmcsd_sdio.c b/drivers/mmcsd/mmcsd_sdio.c
index 9507ffbf0c4..a9cdf7fbf7e 100644
--- a/drivers/mmcsd/mmcsd_sdio.c
+++ b/drivers/mmcsd/mmcsd_sdio.c
@@ -116,11 +116,11 @@
         } \
       else \
         { \
-          nxsig_usleep(usec); \
+          nxsched_usleep(usec); \
         } \
     } while (0)
 #else
-#  define MMCSD_USLEEP(usec) nxsig_usleep(usec)
+#  define MMCSD_USLEEP(usec) nxsched_usleep(usec)
 #endif
 
 /****************************************************************************
diff --git a/drivers/mmcsd/mmcsd_spi.c b/drivers/mmcsd/mmcsd_spi.c
index a6e71fe3cdc..f2c91582e39 100644
--- a/drivers/mmcsd/mmcsd_spi.c
+++ b/drivers/mmcsd/mmcsd_spi.c
@@ -468,7 +468,7 @@ static int mmcsd_waitready(FAR struct mmcsd_slot_s *slot)
         {
           /* Give other threads time to run */
 
-          nxsig_usleep(10000);
+          nxsched_usleep(10000);
         }
     }
   while (elapsed < MMCSD_DELAY_500MS);
diff --git a/drivers/mmcsd/sdio.c b/drivers/mmcsd/sdio.c
index cb6a5f9b388..febae3681b8 100644
--- a/drivers/mmcsd/sdio.c
+++ b/drivers/mmcsd/sdio.c
@@ -532,7 +532,7 @@ int sdio_enable_function(FAR struct sdio_dev_s *dev, uint8_t function)
 
   while (loops-- > 0)
     {
-      nxsig_usleep(10 * 1000);
+      nxsched_usleep(10 * 1000);
 
       ret = sdio_io_rw_direct(dev, false, 0, SDIO_CCCR_IORDY, 0, &value);
       if (ret != OK)
diff --git a/drivers/modem/alt1250/alt1250.c b/drivers/modem/alt1250/alt1250.c
index 87480b5a095..497ee0334a8 100644
--- a/drivers/modem/alt1250/alt1250.c
+++ b/drivers/modem/alt1250/alt1250.c
@@ -1072,7 +1072,7 @@ static int altcom_recvthread(int argc, FAR char *argv[])
                * does not accept any requests and must stay alive.
                */
 
-              nxsig_sleep(1);
+              nxsched_sleep(1);
             }
         }
       else if (ret == ALTMDM_RETURN_EXIT)
diff --git a/drivers/motor/a4988.c b/drivers/motor/a4988.c
index b4b5bdbaa5e..43fb5136770 100644
--- a/drivers/motor/a4988.c
+++ b/drivers/motor/a4988.c
@@ -141,7 +141,7 @@ static int a4988_work(FAR struct stepper_lowerhalf_s *dev,
   if (priv->auto_idle)
     {
       priv->ops->idle(false);
-      nxsig_usleep(USEC_PER_MSEC);
+      nxsched_usleep(USEC_PER_MSEC);
     }
 
   dev->status.state = STEPPER_STATE_RUN;
@@ -201,7 +201,7 @@ static int a4988_idle(FAR struct stepper_lowerhalf_s *dev, uint8_t idle)
   else
     {
       priv->ops->idle(false);
-      nxsig_usleep(USEC_PER_MSEC);
+      nxsched_usleep(USEC_PER_MSEC);
       dev->status.state = STEPPER_STATE_READY;
     }
 
diff --git a/drivers/motor/drv8825.c b/drivers/motor/drv8825.c
index 88b5e214dc1..1eb8c115a4b 100644
--- a/drivers/motor/drv8825.c
+++ b/drivers/motor/drv8825.c
@@ -147,7 +147,7 @@ static int drv8825_work(FAR struct stepper_lowerhalf_s *dev,
   if (priv->auto_idle)
     {
       priv->ops->idle(false);
-      nxsig_usleep(USEC_PER_MSEC * 2);
+      nxsched_usleep(USEC_PER_MSEC * 2);
     }
 
   dev->status.state = STEPPER_STATE_RUN;
@@ -225,7 +225,7 @@ static int drv8825_idle(FAR struct stepper_lowerhalf_s *dev, uint8_t idle)
   else
     {
       priv->ops->idle(false);
-      nxsig_usleep(USEC_PER_MSEC * 2);
+      nxsched_usleep(USEC_PER_MSEC * 2);
       dev->status.state = STEPPER_STATE_READY;
     }
 
diff --git a/drivers/mtd/at24xx.c b/drivers/mtd/at24xx.c
index 7942b07e601..f12e594fb8f 100644
--- a/drivers/mtd/at24xx.c
+++ b/drivers/mtd/at24xx.c
@@ -292,7 +292,7 @@ static int at24c_eraseall(FAR struct at24c_dev_s *priv)
               return -ETIMEDOUT;
             }
 
-          nxsig_usleep(1000);
+          nxsched_usleep(1000);
         }
 
       at24c_i2c_write(priv,
@@ -368,7 +368,7 @@ static ssize_t at24c_read_internal(FAR struct at24c_dev_s *priv,
           return -ETIMEDOUT;
         }
 
-      nxsig_usleep(1000);
+      nxsched_usleep(1000);
     }
 
   /* Then transfer the following bytes */
@@ -492,7 +492,7 @@ static ssize_t at24c_bwrite(FAR struct mtd_dev_s *dev, off_t startblock,
               return -ETIMEDOUT;
             }
 
-          nxsig_usleep(1000);
+          nxsched_usleep(1000);
         }
 
       memcpy(&buf[AT24XX_ADDRSIZE], buffer, priv->pagesize);
diff --git a/drivers/mtd/at25.c b/drivers/mtd/at25.c
index 9694ce4c5be..70054531f7c 100644
--- a/drivers/mtd/at25.c
+++ b/drivers/mtd/at25.c
@@ -308,7 +308,7 @@ static void at25_waitwritecomplete(struct at25_dev_s *priv)
       if ((status & AT25_SR_BUSY) != 0)
         {
           at25_unlock(priv->dev);
-          nxsig_usleep(10000);
+          nxsched_usleep(10000);
           at25_lock(priv->dev);
         }
     }
diff --git a/drivers/mtd/at25ee.c b/drivers/mtd/at25ee.c
index c23be9aac08..952659c3e03 100644
--- a/drivers/mtd/at25ee.c
+++ b/drivers/mtd/at25ee.c
@@ -388,7 +388,7 @@ static void at25ee_waitwritecomplete(struct at25ee_dev_s *priv)
 
       if ((status & AT25EE_SR_WIP) != 0)
         {
-          nxsig_usleep(1000);
+          nxsched_usleep(1000);
         }
     }
   while ((status & AT25EE_SR_WIP) != 0);
diff --git a/drivers/mtd/gd25.c b/drivers/mtd/gd25.c
index c04f6d20222..d4fbaf18512 100644
--- a/drivers/mtd/gd25.c
+++ b/drivers/mtd/gd25.c
@@ -403,7 +403,7 @@ static uint8_t gd25_waitwritecomplete(FAR struct gd25_dev_s *priv)
       if (priv->prev_instr != GD25_PP && (status & GD25_SR_WIP) != 0)
         {
           gd25_unlock(priv->spi);
-          nxsig_usleep(1000);
+          nxsched_usleep(1000);
           gd25_lock(priv->spi);
         }
     }
diff --git a/drivers/mtd/gd55.c b/drivers/mtd/gd55.c
index 87cb1e8e455..00066fb084b 100644
--- a/drivers/mtd/gd55.c
+++ b/drivers/mtd/gd55.c
@@ -710,7 +710,7 @@ static int gd55_erase_sector(FAR struct gd55_dev_s *priv, off_t sector)
 
   do
     {
-      nxsig_usleep(10 * 1000); /* Typical sector erase time is 30ms */
+      nxsched_usleep(10 * 1000); /* Typical sector erase time is 30ms */
       status = gd55_read_status1(priv);
     }
   while ((status & GD55_SR_WIP) != 0);
@@ -780,7 +780,7 @@ static int gd55_erase_64kblock(FAR struct gd55_dev_s *priv, off_t sector)
 
   do
     {
-      nxsig_usleep(50 * 1000); /* typical 64k erase time is 220ms */
+      nxsched_usleep(50 * 1000); /* typical 64k erase time is 220ms */
       status = gd55_read_status1(priv);
     }
   while ((status & GD55_SR_WIP) != 0);
@@ -848,7 +848,7 @@ static int gd55_erase_32kblock(FAR struct gd55_dev_s *priv, off_t sector)
 
   do
     {
-      nxsig_usleep(50 * 1000); /* typical 32k erase time is 150ms */
+      nxsched_usleep(50 * 1000); /* typical 32k erase time is 150ms */
       status = gd55_read_status1(priv);
     }
   while ((status & GD55_SR_WIP) != 0);
@@ -900,7 +900,7 @@ static int gd55_erase_chip(FAR struct gd55_dev_s *priv)
 
   while ((status & GD55_SR_WIP) != 0)
     {
-      nxsig_sleep(2);
+      nxsched_sleep(2);
       status = gd55_read_status1(priv);
     }
 
diff --git a/drivers/mtd/gd5f.c b/drivers/mtd/gd5f.c
index a13126ac09c..c6deb72918d 100644
--- a/drivers/mtd/gd5f.c
+++ b/drivers/mtd/gd5f.c
@@ -336,7 +336,7 @@ static bool gd5f_waitstatus(FAR struct gd5f_dev_s *priv,
       /* Deselect the FLASH */
 
       SPI_SELECT(priv->dev, SPIDEV_FLASH(priv->spi_devid), false);
-      nxsig_usleep(1000);
+      nxsched_usleep(1000);
     }
   while ((status & GD5F_SR_OIP) != 0);
 
diff --git a/drivers/mtd/is25xp.c b/drivers/mtd/is25xp.c
index 87440d68cf3..2bcf374cfbc 100644
--- a/drivers/mtd/is25xp.c
+++ b/drivers/mtd/is25xp.c
@@ -459,7 +459,7 @@ static void is25xp_waitwritecomplete(struct is25xp_dev_s *priv)
       if ((status & IS25_SR_WIP) != 0)
         {
           is25xp_unlock(priv->dev);
-          nxsig_usleep(1000);
+          nxsched_usleep(1000);
           is25xp_lock(priv->dev);
         }
     }
diff --git a/drivers/mtd/m25px.c b/drivers/mtd/m25px.c
index 03678da6215..c20f70014af 100644
--- a/drivers/mtd/m25px.c
+++ b/drivers/mtd/m25px.c
@@ -564,7 +564,7 @@ static void m25p_waitwritecomplete(struct m25p_dev_s *priv)
       if ((status & M25P_SR_WIP) != 0)
         {
           m25p_unlock(priv->dev);
-          nxsig_usleep(1000);
+          nxsched_usleep(1000);
           m25p_lock(priv->dev);
         }
     }
diff --git a/drivers/mtd/mx25lx.c b/drivers/mtd/mx25lx.c
index 1e55b2916e1..bc2a5f7e2cf 100644
--- a/drivers/mtd/mx25lx.c
+++ b/drivers/mtd/mx25lx.c
@@ -462,7 +462,7 @@ static void mx25l_waitwritecomplete(FAR struct mx25l_dev_s *priv)
       if ((status & MX25L_SR_WIP) != 0)
         {
           mx25l_unlock(priv->dev);
-          nxsig_usleep(1000);
+          nxsched_usleep(1000);
           mx25l_lock(priv->dev);
         }
     }
diff --git a/drivers/mtd/mx25rxx.c b/drivers/mtd/mx25rxx.c
index 3437ec7947c..46558cfe8b5 100644
--- a/drivers/mtd/mx25rxx.c
+++ b/drivers/mtd/mx25rxx.c
@@ -467,7 +467,7 @@ int mx25rxx_erase_sector(FAR struct mx25rxx_dev_s *priv, off_t sector)
 
   do
     {
-      nxsig_usleep(50 * 1000);
+      nxsched_usleep(50 * 1000);
       mx25rxx_read_status(priv);
       status = priv->cmdbuf[0];
     }
@@ -492,7 +492,7 @@ int mx25rxx_erase_block(FAR struct mx25rxx_dev_s *priv, off_t block)
 
   do
     {
-      nxsig_usleep(300 * 1000);
+      nxsched_usleep(300 * 1000);
       mx25rxx_read_status(priv);
       status = priv->cmdbuf[0];
     }
@@ -518,7 +518,7 @@ int mx25rxx_erase_chip(FAR struct mx25rxx_dev_s *priv)
 
   while ((status & MX25R_SR_WIP) != 0)
     {
-      nxsig_sleep(2);
+      nxsched_sleep(2);
       mx25rxx_read_status(priv);
       status = priv->cmdbuf[0];
     }
diff --git a/drivers/mtd/mx35.c b/drivers/mtd/mx35.c
index f602bc6ae20..b74b35f5402 100644
--- a/drivers/mtd/mx35.c
+++ b/drivers/mtd/mx35.c
@@ -382,7 +382,7 @@ static bool mx35_waitstatus(FAR struct mx35_dev_s *priv,
        * case will allow other peripherals to access the SPI bus.
        */
     }
-  while (((status & MX35_SR_OIP) != 0) && (!nxsig_usleep(1000)));
+  while (((status & MX35_SR_OIP) != 0) && (!nxsched_usleep(1000)));
 
   mx35info("Complete\n");
   return successif ? ((status & mask) != 0) : ((status & mask) == 0);
diff --git a/drivers/mtd/n25qxxx.c b/drivers/mtd/n25qxxx.c
index bde0dc88f40..fa261f27560 100644
--- a/drivers/mtd/n25qxxx.c
+++ b/drivers/mtd/n25qxxx.c
@@ -891,7 +891,7 @@ static int n25qxxx_erase_chip(FAR struct n25qxxx_dev_s *priv)
   status = n25qxxx_read_status(priv);
   while ((status & STATUS_BUSY_MASK) != 0)
     {
-      nxsig_usleep(200 * 1000);
+      nxsched_usleep(200 * 1000);
       status = n25qxxx_read_status(priv);
     }
 
diff --git a/drivers/mtd/s25fl1.c b/drivers/mtd/s25fl1.c
index b85db789187..6a17f297295 100644
--- a/drivers/mtd/s25fl1.c
+++ b/drivers/mtd/s25fl1.c
@@ -930,7 +930,7 @@ static int s25fl1_erase_chip(FAR struct s25fl1_dev_s *priv)
   status = sf25fl1_read_status1(priv);
   while ((status & STATUS1_BUSY_MASK) != 0)
     {
-      nxsig_usleep(200 * 1000);
+      nxsched_usleep(200 * 1000);
       status = sf25fl1_read_status1(priv);
     }
 
@@ -1614,7 +1614,7 @@ FAR struct mtd_dev_s *s25fl1_initialize(FAR struct qspi_dev_s *qspi,
           priv->cmdbuf[1] |= STATUS2_QUAD_ENABLE;
           s25fl1_write_status(priv);
           priv->cmdbuf[1] = sf25fl1_read_status2(priv);
-          nxsig_usleep(50 * 1000);
+          nxsched_usleep(50 * 1000);
         }
 
       /* Unprotect FLASH sectors if so requested. */
diff --git a/drivers/mtd/sst25.c b/drivers/mtd/sst25.c
index c918b9b8df4..faba4fa6aae 100644
--- a/drivers/mtd/sst25.c
+++ b/drivers/mtd/sst25.c
@@ -447,7 +447,7 @@ static uint8_t sst25_waitwritecomplete(struct sst25_dev_s *priv)
       if ((status & SST25_SR_BUSY) != 0)
         {
           sst25_unlock(priv->dev);
-          nxsig_usleep(1000);
+          nxsched_usleep(1000);
           sst25_lock(priv->dev);
         }
 #endif
diff --git a/drivers/mtd/sst25xx.c b/drivers/mtd/sst25xx.c
index 83dfd4a1cce..270894c6456 100644
--- a/drivers/mtd/sst25xx.c
+++ b/drivers/mtd/sst25xx.c
@@ -345,7 +345,7 @@ static void sst25xx_waitwritecomplete(struct sst25xx_dev_s *priv)
       if ((status & SST25_SR_WIP) != 0)
         {
           sst25xx_unlock(priv->dev);
-          nxsig_usleep(1000);
+          nxsched_usleep(1000);
           sst25xx_lock(priv->dev);
         }
     }
diff --git a/drivers/mtd/sst26.c b/drivers/mtd/sst26.c
index 824e67488b9..aba8acad8a0 100644
--- a/drivers/mtd/sst26.c
+++ b/drivers/mtd/sst26.c
@@ -414,7 +414,7 @@ static void sst26_waitwritecomplete(struct sst26_dev_s *priv)
       if ((status & SST26_SR_WIP) != 0)
         {
           sst26_unlock(priv->dev);
-          nxsig_usleep(1000);
+          nxsched_usleep(1000);
           sst26_lock(priv->dev);
         }
     }
diff --git a/drivers/mtd/sst39vf.c b/drivers/mtd/sst39vf.c
index 1a33dc58f26..642d28af138 100644
--- a/drivers/mtd/sst39vf.c
+++ b/drivers/mtd/sst39vf.c
@@ -433,12 +433,12 @@ static int sst39vf_chiperase(FAR struct sst39vf_dev_s *priv)
 
       /* No, wait one system clock tick */
 
-      nxsig_usleep(USEC_PER_TICK);
+      nxsched_usleep(USEC_PER_TICK);
     }
 #else
   /* Delay the maximum amount of time for the chip erase to complete. */
 
-  nxsig_usleep(SST39VF_TSCE_MSEC * USEC_PER_MSEC);
+  nxsched_usleep(SST39VF_TSCE_MSEC * USEC_PER_MSEC);
 #endif
 
   return OK;
@@ -509,12 +509,12 @@ static int sst39vf_sectorerase(FAR struct sst39vf_dev_s *priv,
 
       /* No, wait one system clock tick */
 
-      nxsig_usleep(USEC_PER_TICK);
+      nxsched_usleep(USEC_PER_TICK);
     }
 #else
   /* Delay the maximum amount of time for the sector erase to complete. */
 
-  nxsig_usleep(SST39VF_TSE_MSEC * USEC_PER_MSEC);
+  nxsched_usleep(SST39VF_TSE_MSEC * USEC_PER_MSEC);
 #endif
 
   return OK;
diff --git a/drivers/mtd/w25.c b/drivers/mtd/w25.c
index e6344405cbc..a5ef7b560cd 100644
--- a/drivers/mtd/w25.c
+++ b/drivers/mtd/w25.c
@@ -579,7 +579,7 @@ static uint8_t w25_waitwritecomplete(struct w25_dev_s *priv)
       if (priv->prev_instr != W25_PP && (status & W25_SR_BUSY) != 0)
         {
           w25_unlock(priv->spi);
-          nxsig_usleep(1000);
+          nxsched_usleep(1000);
           w25_lock(priv->spi);
         }
     }
diff --git a/drivers/mtd/w25qxxxjv.c b/drivers/mtd/w25qxxxjv.c
index eba035316d9..94f15ada09d 100644
--- a/drivers/mtd/w25qxxxjv.c
+++ b/drivers/mtd/w25qxxxjv.c
@@ -985,7 +985,7 @@ static int w25qxxxjv_erase_sector(FAR struct w25qxxxjv_dev_s *priv,
           return -EBUSY;
         }
 
-      nxsig_usleep(priv->erasetime * 1000);
+      nxsched_usleep(priv->erasetime * 1000);
       status = w25qxxxjv_read_status(priv);
     }
 
@@ -1008,7 +1008,7 @@ static int w25qxxxjv_erase_sector(FAR struct w25qxxxjv_dev_s *priv,
   status = w25qxxxjv_read_status(priv);
   while ((status & STATUS_BUSY_MASK) != 0)
     {
-      nxsig_usleep(priv->erasetime * 1000);
+      nxsched_usleep(priv->erasetime * 1000);
       status = w25qxxxjv_read_status(priv);
     }
 
@@ -1042,7 +1042,7 @@ static int w25qxxxjv_erase_chip(FAR struct w25qxxxjv_dev_s *priv)
   status = w25qxxxjv_read_status(priv);
   while ((status & STATUS_BUSY_MASK) != 0)
     {
-      nxsig_usleep(200 * 1000);
+      nxsched_usleep(200 * 1000);
       status = w25qxxxjv_read_status(priv);
     }
 
diff --git a/drivers/net/slip.c b/drivers/net/slip.c
index f9622a63e0a..7ca1dd118bc 100644
--- a/drivers/net/slip.c
+++ b/drivers/net/slip.c
@@ -299,7 +299,7 @@ static void slip_transmit(FAR struct slip_driver_s *self)
                            self->txlen - self->txsent);
           if (ssz <= 0)
             {
-              nxsig_usleep(10000);
+              nxsched_usleep(10000);
               i++;
               continue;
             }
diff --git a/drivers/net/w5500.c b/drivers/net/w5500.c
index f79eaeafd12..a968a691a96 100644
--- a/drivers/net/w5500.c
+++ b/drivers/net/w5500.c
@@ -471,11 +471,11 @@ static void w5500_reset(FAR struct w5500_driver_s *self, bool keep)
 
   if (!keep)
     {
-      nxsig_usleep(500);   /* [W5500]: T_RC (Reset Cycle Time) min 500 us   */
+      nxsched_usleep(500);   /* [W5500]: T_RC (Reset Cycle Time) min 500 us   */
 
       self->lower->reset(self->lower, false);
 
-      nxsig_usleep(1000);  /* [W5500]: T_PL (RSTn to internal PLL lock) 1ms */
+      nxsched_usleep(1000);  /* [W5500]: T_PL (RSTn to internal PLL lock) 1ms */
     }
 }
 
@@ -1054,7 +1054,7 @@ static int w5500_unfence(FAR struct w5500_driver_s *self)
                           W5500_BSB_COMMON_REGS,
                           W5500_PHYCFGR);
 
-      nxsig_usleep(100000); /* 100 ms x 100 = 10 sec */
+      nxsched_usleep(100000); /* 100 ms x 100 = 10 sec */
     }
 
   if (value & PHYCFGR_LNK)
diff --git a/drivers/power/battery/bq2425x.c b/drivers/power/battery/bq2425x.c
index 746cd3b54a0..c31e7f0ae24 100644
--- a/drivers/power/battery/bq2425x.c
+++ b/drivers/power/battery/bq2425x.c
@@ -276,7 +276,7 @@ static inline int bq2425x_reset(FAR struct bq2425x_dev_s *priv)
 
   /* Wait a little bit to clear registers */
 
-  nxsig_usleep(500);
+  nxsched_usleep(500);
 
   /* There is a BUG in BQ2425X the RESET bit is always read as 1 */
 
diff --git a/drivers/power/battery/bq2429x.c b/drivers/power/battery/bq2429x.c
index 216dee17c0a..9cd3b9cb3d5 100644
--- a/drivers/power/battery/bq2429x.c
+++ b/drivers/power/battery/bq2429x.c
@@ -325,7 +325,7 @@ static int bq2429x_reset(FAR struct bq2429x_dev_s *priv)
 
   /* Wait a little bit to clear registers */
 
-  nxsig_usleep(500);
+  nxsched_usleep(500);
 
 #if 0
   /* There is a BUG in BQ2429X the RESET bit is always read as 1 */
diff --git a/drivers/power/battery/bq769x0.c b/drivers/power/battery/bq769x0.c
index 2a74d6a74c4..77bcbb9dd48 100644
--- a/drivers/power/battery/bq769x0.c
+++ b/drivers/power/battery/bq769x0.c
@@ -1622,7 +1622,7 @@ static int bq769x0_getcurrent(FAR struct bq769x0_dev_s *priv,
 
       /* Sample is not complete, wait and try again */
 
-      nxsig_usleep(BQ769X0_CC_POLL_INTERVAL * USEC_PER_MSEC);
+      nxsched_usleep(BQ769X0_CC_POLL_INTERVAL * USEC_PER_MSEC);
     }
 
   /* CC value didn't become available in the expected amount of time */
diff --git a/drivers/power/supply/regulator.c b/drivers/power/supply/regulator.c
index 59bd5642bd7..5c36f62b6cd 100644
--- a/drivers/power/supply/regulator.c
+++ b/drivers/power/supply/regulator.c
@@ -766,7 +766,7 @@ int regulator_enable_delay(FAR struct regulator_s *regulator, int ms)
   ret = regulator_enable(regulator);
   if (!ret)
     {
-      nxsig_usleep(1000 * ms);
+      nxsched_usleep(1000 * ms);
     }
 
   return ret;
diff --git a/drivers/rpmsg/rpmsg_ping.c b/drivers/rpmsg/rpmsg_ping.c
index d2873af0acc..8e315ee89a1 100644
--- a/drivers/rpmsg/rpmsg_ping.c
+++ b/drivers/rpmsg/rpmsg_ping.c
@@ -248,7 +248,7 @@ int rpmsg_ping(FAR struct rpmsg_endpoint *ept,
 
       if (ping->sleep > 0)
         {
-          nxsig_usleep(ping->sleep * USEC_PER_MSEC);
+          nxsched_usleep(ping->sleep * USEC_PER_MSEC);
         }
     }
 
diff --git a/drivers/rpmsg/rpmsg_port_uart.c b/drivers/rpmsg/rpmsg_port_uart.c
index 0e8650dde73..cf49e05ab2f 100644
--- a/drivers/rpmsg/rpmsg_port_uart.c
+++ b/drivers/rpmsg/rpmsg_port_uart.c
@@ -409,7 +409,7 @@ static int rpmsg_port_uart_tx_thread(int argc, FAR char *argv[])
     {
       while (!rpuart->connected)
         {
-          nxsig_usleep(100000);
+          nxsched_usleep(100000);
         }
 
       while ((hdr = rpmsg_port_queue_get_buffer(txq, true)) != NULL)
diff --git a/drivers/sensors/adxl345_base.c b/drivers/sensors/adxl345_base.c
index 3d998e230cb..9efcdd692e0 100644
--- a/drivers/sensors/adxl345_base.c
+++ b/drivers/sensors/adxl345_base.c
@@ -314,7 +314,7 @@ static void adxl345_reset(FAR struct adxl345_dev_s *priv)
 
   /* Wait a bit to make the GOD of TIME happy */
 
-  nxsig_usleep(20 * 1000);
+  nxsched_usleep(20 * 1000);
 }
 
 /****************************************************************************
diff --git a/drivers/sensors/adxl362_uorb.c b/drivers/sensors/adxl362_uorb.c
index ce2542079de..dbb7ad628e4 100644
--- a/drivers/sensors/adxl362_uorb.c
+++ b/drivers/sensors/adxl362_uorb.c
@@ -550,7 +550,7 @@ static int adxl362_thread(int argc, FAR char **argv)
 
       /* Sleeping thread before fetching the next sensor data */
 
-      nxsig_usleep(priv->interval);
+      nxsched_usleep(priv->interval);
     }
 
   return OK;
diff --git a/drivers/sensors/adxl372_uorb.c b/drivers/sensors/adxl372_uorb.c
index 5f7d4fc6483..460d4a9c642 100644
--- a/drivers/sensors/adxl372_uorb.c
+++ b/drivers/sensors/adxl372_uorb.c
@@ -514,7 +514,7 @@ static int adxl372_thread(int argc, FAR char **argv)
 
       /* Sleeping thread before fetching the next sensor data */
 
-      nxsig_usleep(priv->interval);
+      nxsched_usleep(priv->interval);
     }
 
   return OK;
diff --git a/drivers/sensors/aht10.c b/drivers/sensors/aht10.c
index b9e1b85d4d6..5cf0018bf9a 100644
--- a/drivers/sensors/aht10.c
+++ b/drivers/sensors/aht10.c
@@ -208,7 +208,7 @@ static int aht10_initialize(FAR struct aht10_dev_s *priv)
 
   /* wait at least 300ms */
 
-  nxsig_usleep(300000);
+  nxsched_usleep(300000);
 
   buf[0] = 0x08;
   buf[1] = 0x00;
@@ -222,7 +222,7 @@ static int aht10_initialize(FAR struct aht10_dev_s *priv)
 
   /* wait at least 300ms */
 
-  nxsig_usleep(300000);
+  nxsched_usleep(300000);
 
   return ret;
 }
diff --git a/drivers/sensors/apds9922.c b/drivers/sensors/apds9922.c
index ffcb28eefb0..a2ee99c355e 100644
--- a/drivers/sensors/apds9922.c
+++ b/drivers/sensors/apds9922.c
@@ -560,7 +560,7 @@ static int apds9922_reset(FAR struct apds9922_dev_s *priv)
 
   /* Wait for device to power up properly after reset */
 
-  nxsig_usleep(50000);
+  nxsched_usleep(50000);
 
   return OK;
 }
diff --git a/drivers/sensors/apds9960.c b/drivers/sensors/apds9960.c
index a7378d7e29d..96d04fbea59 100644
--- a/drivers/sensors/apds9960.c
+++ b/drivers/sensors/apds9960.c
@@ -985,7 +985,7 @@ static int apds9960_readgesture(FAR struct apds9960_dev_s *priv)
     {
       /* Wait some time to collect next batch of FIFO data */
 
-      nxsig_usleep(FIFO_PAUSE_TIME);
+      nxsched_usleep(FIFO_PAUSE_TIME);
 
       /* Get the contents of the STATUS register. Is data still valid? */
 
@@ -1081,7 +1081,7 @@ static int apds9960_readgesture(FAR struct apds9960_dev_s *priv)
         {
           /* Determine best guessed gesture and clean up */
 
-          nxsig_usleep(FIFO_PAUSE_TIME);
+          nxsched_usleep(FIFO_PAUSE_TIME);
           apds9960_decodegesture(priv);
           motion = priv->gesture_motion;
 
@@ -1226,7 +1226,7 @@ int apds9960_register(FAR const char *devpath,
 
   /* Wait 100ms */
 
-  nxsig_usleep(100000);
+  nxsched_usleep(100000);
 
   /* Initialize the device (leave RESET) */
 
diff --git a/drivers/sensors/as726x.c b/drivers/sensors/as726x.c
index 059e6ed9b89..17826645c07 100644
--- a/drivers/sensors/as726x.c
+++ b/drivers/sensors/as726x.c
@@ -214,7 +214,7 @@ static uint8_t as726x_read8(FAR struct as726x_dev_s *priv, uint8_t regaddr)
           break;  /* If TX bit is clear, it is ok to write */
         }
 
-      nxsig_usleep(AS726X_POLLING_DELAY);
+      nxsched_usleep(AS726X_POLLING_DELAY);
     }
 
   /* Send the virtual register address (bit 7 should be 0 to indicate we are
@@ -233,7 +233,7 @@ static uint8_t as726x_read8(FAR struct as726x_dev_s *priv, uint8_t regaddr)
           break;  /* Read data is ready. */
         }
 
-      nxsig_usleep(AS726X_POLLING_DELAY);
+      nxsched_usleep(AS726X_POLLING_DELAY);
     }
 
   uint8_t incoming = read_register(priv, AS72XX_SLAVE_READ_REG);
@@ -289,7 +289,7 @@ static void as726x_write8(FAR struct as726x_dev_s *priv, uint8_t regaddr,
           break;
         }
 
-      nxsig_usleep(AS726X_POLLING_DELAY);
+      nxsched_usleep(AS726X_POLLING_DELAY);
     }
 
   /* Send the virtual register address (setting bit 7 to indicate we are
@@ -310,7 +310,7 @@ static void as726x_write8(FAR struct as726x_dev_s *priv, uint8_t regaddr,
           break;
         }
 
-      nxsig_usleep(AS726X_POLLING_DELAY);
+      nxsched_usleep(AS726X_POLLING_DELAY);
     }
 
   /* Send the data to complete the operation. */
diff --git a/drivers/sensors/bh1749nuc_uorb.c b/drivers/sensors/bh1749nuc_uorb.c
index 11f03582568..4ccaeaa186c 100644
--- a/drivers/sensors/bh1749nuc_uorb.c
+++ b/drivers/sensors/bh1749nuc_uorb.c
@@ -384,7 +384,7 @@ static int bh1749nuc_thread(int argc, FAR char **argv)
       /* Sleeping thread before fetching the next sensor data */
 
       min_interval = MIN(rgb->interval, ir->interval);
-      nxsig_usleep(min_interval);
+      nxsched_usleep(min_interval);
     }
 
   return OK;
diff --git a/drivers/sensors/bme680_uorb.c b/drivers/sensors/bme680_uorb.c
index ab2dfcfa7de..f23d2ea849e 100644
--- a/drivers/sensors/bme680_uorb.c
+++ b/drivers/sensors/bme680_uorb.c
@@ -1601,7 +1601,7 @@ static int bme680_thread(int argc, char **argv)
         }
 
     thread_sleep:
-      nxsig_usleep(CONFIG_SENSORS_BME680_POLL_INTERVAL);
+      nxsched_usleep(CONFIG_SENSORS_BME680_POLL_INTERVAL);
     }
 
   return OK;
diff --git a/drivers/sensors/bme688_uorb.c b/drivers/sensors/bme688_uorb.c
index f6f73e66c2b..8b41137b678 100644
--- a/drivers/sensors/bme688_uorb.c
+++ b/drivers/sensors/bme688_uorb.c
@@ -1601,7 +1601,7 @@ static int bme688_thread(int argc, char **argv)
         }
 
     thread_sleep:
-      nxsig_usleep(CONFIG_SENSORS_BME688_POLL_INTERVAL);
+      nxsched_usleep(CONFIG_SENSORS_BME688_POLL_INTERVAL);
     }
 
   return OK;
diff --git a/drivers/sensors/bmi088_uorb.c b/drivers/sensors/bmi088_uorb.c
index f9ea6d49334..267670a2aa2 100644
--- a/drivers/sensors/bmi088_uorb.c
+++ b/drivers/sensors/bmi088_uorb.c
@@ -321,7 +321,7 @@ static void bmi088_gyro_enable(FAR struct bmi088_gyro_dev_uorb_s *priv,
       bmi088_put_gyro_reg8(&priv->dev, BMI088_GYRO_LPM1 ,
                                        BMI088_GYRO_PM_NORMAL);
 
-      nxsig_usleep(30000);
+      nxsched_usleep(30000);
 
       idx_odr   = bmi088_find_parameter(priv->interval,
                                         g_bmi088_gyro_odr,
@@ -730,7 +730,7 @@ static int bmi088_register_accel(int devno,
   /* BMI088 detects communication bus is SPI by rising edge of CS. */
 
   bmi088_get_acc_reg8(&priv->dev , BMI088_ACC_CHIP_ID);
-  nxsig_usleep(200);
+  nxsched_usleep(200);
 
 #endif
 
diff --git a/drivers/sensors/bmi160_uorb.c b/drivers/sensors/bmi160_uorb.c
index 1c9877313dc..6acd1e0386a 100644
--- a/drivers/sensors/bmi160_uorb.c
+++ b/drivers/sensors/bmi160_uorb.c
@@ -209,7 +209,7 @@ static void bmi160_accel_enable(FAR struct bmi160_dev_uorb_s *priv,
       /* Set accel as normal mode. */
 
       bmi160_putreg8(&priv->dev, BMI160_CMD, ACCEL_PM_NORMAL);
-      nxsig_usleep(30000);
+      nxsched_usleep(30000);
 
       idx = bmi160_findodr(priv->interval, g_bmi160_accel_odr,
                            nitems(g_bmi160_accel_odr));
@@ -260,7 +260,7 @@ static void bmi160_gyro_enable(FAR struct bmi160_dev_uorb_s *priv,
       /* Set gyro as normal mode. */
 
       bmi160_putreg8(&priv->dev, BMI160_CMD, GYRO_PM_NORMAL);
-      nxsig_usleep(30000);
+      nxsched_usleep(30000);
 
       idx = bmi160_findodr(priv->interval, g_bmi160_gyro_odr,
                            nitems(g_bmi160_gyro_odr));
@@ -597,7 +597,7 @@ static int bmi160_register_accel(int devno,
 
   bmi160_getreg8(&priv->dev, 0x7f);
   bmi160_getreg8(&priv->dev, 0x7f); /* workaround: fail to switch SPI, run twice */
-  nxsig_usleep(200);
+  nxsched_usleep(200);
 
 #endif
 
diff --git a/drivers/sensors/bmi270_uorb.c b/drivers/sensors/bmi270_uorb.c
index e1b6cd139f7..91405043710 100644
--- a/drivers/sensors/bmi270_uorb.c
+++ b/drivers/sensors/bmi270_uorb.c
@@ -549,7 +549,7 @@ static int bmi270_thread(int argc, FAR char **argv)
       /* Sleeping thread before fetching the next sensor data */
 
       min_interval = MIN(accel->interval, gyro->interval);
-      nxsig_usleep(min_interval);
+      nxsched_usleep(min_interval);
     }
 
   return OK;
diff --git a/drivers/sensors/bmm150_uorb.c b/drivers/sensors/bmm150_uorb.c
index 8a732b6e019..09fda966f9d 100644
--- a/drivers/sensors/bmm150_uorb.c
+++ b/drivers/sensors/bmm150_uorb.c
@@ -654,7 +654,7 @@ static int bmm150_thread(int argc, FAR char **argv)
 
       /* Sleeping thread before fetching the next sensor data */
 
-      nxsig_usleep(dev->interval);
+      nxsched_usleep(dev->interval);
     }
 
   return OK;
diff --git a/drivers/sensors/bmp180_base.c b/drivers/sensors/bmp180_base.c
index 24f94d2a3a8..e388e1ea33a 100644
--- a/drivers/sensors/bmp180_base.c
+++ b/drivers/sensors/bmp180_base.c
@@ -259,7 +259,7 @@ void bmp180_read_press_temp(FAR struct bmp180_dev_s *priv)
 
   /* Wait 5ms */
 
-  nxsig_usleep(5000);
+  nxsched_usleep(5000);
 
   /* Read temperature */
 
@@ -271,7 +271,7 @@ void bmp180_read_press_temp(FAR struct bmp180_dev_s *priv)
 
   /* Delay 25.5ms (to OverSampling 8X) */
 
-  nxsig_usleep(25500);
+  nxsched_usleep(25500);
 
   /* Read pressure */
 
diff --git a/drivers/sensors/dhtxx.c b/drivers/sensors/dhtxx.c
index 8e21eeffbe7..db410925991 100644
--- a/drivers/sensors/dhtxx.c
+++ b/drivers/sensors/dhtxx.c
@@ -419,7 +419,7 @@ static int dhtxx_open(FAR struct file *filep)
 
   dht_standby_mode(priv);
 
-  nxsig_sleep(DHTXX_SAMPLING_PERIOD_S);
+  nxsched_sleep(DHTXX_SAMPLING_PERIOD_S);
 
   /* Sensor ready. */
 
@@ -503,7 +503,7 @@ out:
    * consecutive readings.
    */
 
-  nxsig_sleep(DHTXX_SAMPLING_PERIOD_S);
+  nxsched_sleep(DHTXX_SAMPLING_PERIOD_S);
 
   /* Sensor ready for new reading */
 
diff --git a/drivers/sensors/ds18b20_uorb.c b/drivers/sensors/ds18b20_uorb.c
index 0b97ee53e4a..7849f73bac4 100644
--- a/drivers/sensors/ds18b20_uorb.c
+++ b/drivers/sensors/ds18b20_uorb.c
@@ -616,7 +616,7 @@ static int ds18b20_measure_read(FAR struct ds18b20_dev_s *dev,
       return ret;
     }
 
-  nxsig_usleep(g_res_timeout[DS18B20_RES_VAL(dev->reg.res)]);
+  nxsched_usleep(g_res_timeout[DS18B20_RES_VAL(dev->reg.res)]);
 
   ret = ds18b20_read_spad(dev, data->spad);
   if (ret < 0)
@@ -857,7 +857,7 @@ static int ds18b20_thread(int argc, char** argv)
                * is up to date.
                */
 
-              nxsig_usleep(g_res_timeout[DS18B20_RES_VAL(priv->reg.res)]);
+              nxsched_usleep(g_res_timeout[DS18B20_RES_VAL(priv->reg.res)]);
 
               /* Check for existing temperature alarm */
 
@@ -896,7 +896,7 @@ static int ds18b20_thread(int argc, char** argv)
 
       /* Sleeping thread before fetching the next sensor data */
 
-      nxsig_usleep(priv->interval);
+      nxsched_usleep(priv->interval);
     }
 
   return OK;
diff --git a/drivers/sensors/fakesensor_uorb.c b/drivers/sensors/fakesensor_uorb.c
index fa5224cffe3..6077cf9e32c 100644
--- a/drivers/sensors/fakesensor_uorb.c
+++ b/drivers/sensors/fakesensor_uorb.c
@@ -352,7 +352,7 @@ static int fakesensor_thread(int argc, char** argv)
         {
           /* Sleeping thread for interval */
 
-          nxsig_usleep(sensor->batch ? sensor->batch : sensor->interval);
+          nxsched_usleep(sensor->batch ? sensor->batch : sensor->interval);
 
           /* Notify upper */
 
diff --git a/drivers/sensors/fs3000_uorb.c b/drivers/sensors/fs3000_uorb.c
index a9478b04212..47135003799 100644
--- a/drivers/sensors/fs3000_uorb.c
+++ b/drivers/sensors/fs3000_uorb.c
@@ -216,7 +216,7 @@ static int fs3000_thread(int argc, char** argv)
                                  sizeof(struct sensor_velocity));
 
 thread_sleep:
-      nxsig_usleep(CONFIG_SENSORS_FS3000_POLL_INTERVAL);
+      nxsched_usleep(CONFIG_SENSORS_FS3000_POLL_INTERVAL);
     }
 
   return OK;
diff --git a/drivers/sensors/hc_sr04.c b/drivers/sensors/hc_sr04.c
index 6c52f97b9ba..940d1792edb 100644
--- a/drivers/sensors/hc_sr04.c
+++ b/drivers/sensors/hc_sr04.c
@@ -128,7 +128,7 @@ static int hcsr04_start_measuring(FAR struct hcsr04_dev_s *priv)
   /* Send to 10uS trigger pulse */
 
   priv->config->set_trigger(priv->config, true);
-  nxsig_usleep(10);
+  nxsched_usleep(10);
   priv->config->set_trigger(priv->config, false);
 
   return 0;
diff --git a/drivers/sensors/hdc1008.c b/drivers/sensors/hdc1008.c
index a79eb2292f1..4dab56a386e 100644
--- a/drivers/sensors/hdc1008.c
+++ b/drivers/sensors/hdc1008.c
@@ -200,7 +200,7 @@ static int hdc1008_measure_trh(FAR struct hdc1008_dev_s *priv, int *t,
    * both temperature and humidity.
    */
 
-  nxsig_usleep(20000);
+  nxsched_usleep(20000);
 
   ret = i2c_read(priv->i2c, &config, buf, 4);
   if (ret < 0)
@@ -250,7 +250,7 @@ static int hdc1008_measure_t_or_rh(FAR struct hdc1008_dev_s *priv,
    * margin for either temperature/humidity at maximum resolution.
    */
 
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
 
   ret = i2c_read(priv->i2c, &config, buf, 2);
   if (ret < 0)
@@ -902,7 +902,7 @@ static int hdc1008_reset(FAR struct hdc1008_dev_s *priv)
   do
     {
       ret = hdc1008_getreg(priv, HDC1008_REG_CONFIGURATION, &reg);
-      nxsig_usleep(1000);
+      nxsched_usleep(1000);
       --count;
     }
   while ((reg & HDC1008_CONFIGURATION_RST) && (ret == OK) && count);
@@ -974,7 +974,7 @@ int hdc1008_register(FAR const char *devpath, FAR struct i2c_master_s *i2c,
    * sure that it is ready.
    */
 
-  nxsig_usleep(15000);
+  nxsched_usleep(15000);
 
   /* Set default configuration */
 
diff --git a/drivers/sensors/hts221.c b/drivers/sensors/hts221.c
index cd5ae83a4b7..c02154e454a 100644
--- a/drivers/sensors/hts221.c
+++ b/drivers/sensors/hts221.c
@@ -401,7 +401,7 @@ static int hts221_config_ctrl_reg2(FAR struct hts221_dev_s *priv,
               break;
             }
 
-          nxsig_usleep(10 * 1000);
+          nxsched_usleep(10 * 1000);
           retries--;
         }
       while (retries);
diff --git a/drivers/sensors/hyt271_uorb.c b/drivers/sensors/hyt271_uorb.c
index caaef85d3f1..4c3d9367b8c 100644
--- a/drivers/sensors/hyt271_uorb.c
+++ b/drivers/sensors/hyt271_uorb.c
@@ -295,7 +295,7 @@ static int hyt271_mr(FAR struct hyt271_dev_s *dev,
 
   /* Wait until measure cycle is done. This takes between 60 - 100 ms. */
 
-  nxsig_usleep(100000);
+  nxsched_usleep(100000);
   return ret;
 }
 
@@ -368,7 +368,7 @@ static int hyt271_cmd_response(FAR struct hyt271_dev_s *dev,
 
   /* Sleep for usec µs until response is ready */
 
-  nxsig_usleep(usec);
+  nxsched_usleep(usec);
 
   /* Read response and return */
 
@@ -857,7 +857,7 @@ static int hyt271_thread(int argc, char** argv)
 
       /* Sleeping thread before fetching the next sensor data */
 
-      nxsig_usleep(priv->interval);
+      nxsched_usleep(priv->interval);
     }
 
   return OK;
diff --git a/drivers/sensors/kxtj9.c b/drivers/sensors/kxtj9.c
index f443a270da9..84379d39cc1 100644
--- a/drivers/sensors/kxtj9.c
+++ b/drivers/sensors/kxtj9.c
@@ -277,7 +277,7 @@ static void kxtj9_soft_reset(FAR struct kxtj9_dev_s *priv)
 
   /* Delay 10ms for the accel parts to re-initialize */
 
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
 }
 
 /****************************************************************************
diff --git a/drivers/sensors/l86xxx_uorb.c b/drivers/sensors/l86xxx_uorb.c
index 22345e793c2..5aeb0b2b444 100644
--- a/drivers/sensors/l86xxx_uorb.c
+++ b/drivers/sensors/l86xxx_uorb.c
@@ -311,7 +311,7 @@ static int send_command(l86xxx_dev_s *dev,
   if (cmd == SET_NMEA_BAUDRATE)
   {
 #ifdef CONFIG_SERIAL_TERMIOS
-    nxsig_usleep(20000); /* Should wait for a bit before changing interface baud rate */
+    nxsched_usleep(20000); /* Should wait for a bit before changing interface baud rate */
     err = set_baud_rate(dev, (int)arg);
 #else
     err = -EINVAL;
diff --git a/drivers/sensors/lis2dh.c b/drivers/sensors/lis2dh.c
index abf20acf8c9..79790952488 100644
--- a/drivers/sensors/lis2dh.c
+++ b/drivers/sensors/lis2dh.c
@@ -1082,7 +1082,7 @@ static int lis2dh_handle_selftest(FAR struct lis2dh_dev_s *priv)
       goto out;
     }
 
-  nxsig_usleep(20000);
+  nxsched_usleep(20000);
 
   /* Now INT1 should have been latched high and INT2 should be still low */
 
@@ -1114,7 +1114,7 @@ static int lis2dh_handle_selftest(FAR struct lis2dh_dev_s *priv)
           goto out;
         }
 
-      nxsig_usleep(20000);
+      nxsched_usleep(20000);
 
       if (priv->config->read_int2_pin() != 1)
         {
@@ -1221,7 +1221,7 @@ static FAR const struct lis2dh_vector_s *
 
   while (--retries_left > 0)
     {
-      nxsig_usleep(20000);
+      nxsched_usleep(20000);
       if (lis2dh_data_available(dev))
         {
           if (lis2dh_access(dev, ST_LIS2DH_OUT_X_L_REG, retval,
@@ -1676,7 +1676,7 @@ static int lis2dh_reboot(FAR struct lis2dh_dev_s *dev)
           return -ETIMEDOUT;
         }
 
-       nxsig_usleep(1);
+       nxsched_usleep(1);
     }
   while (true);
 
diff --git a/drivers/sensors/lis2mdl_uorb.c b/drivers/sensors/lis2mdl_uorb.c
index 98c9407f36b..e7b194ce77d 100644
--- a/drivers/sensors/lis2mdl_uorb.c
+++ b/drivers/sensors/lis2mdl_uorb.c
@@ -881,7 +881,7 @@ static int lis2mdl_selftest(FAR struct sensor_lowerhalf_s *lower,
 
       /* Wait for the measurement interval */
 
-      nxsig_usleep(ODR_TO_INTERVAL[dev->odr]);
+      nxsched_usleep(ODR_TO_INTERVAL[dev->odr]);
     }
 
   sninfo("LIS2MDL regular samples complete.");
@@ -896,7 +896,7 @@ static int lis2mdl_selftest(FAR struct sensor_lowerhalf_s *lower,
     }
 
   sninfo("LIS2MDL waiting for self-test.");
-  nxsig_usleep(60000); /* Wait 60ms as per AN5069 */
+  nxsched_usleep(60000); /* Wait 60ms as per AN5069 */
   sninfo("LIS2MDL waiting for self-test over.");
 
   for (uint8_t i = 0; i < SELFTEST_SAMPLES; i++)
@@ -922,7 +922,7 @@ static int lis2mdl_selftest(FAR struct sensor_lowerhalf_s *lower,
 
       /* Wait for the measurement interval */
 
-      nxsig_usleep(ODR_TO_INTERVAL[dev->odr]);
+      nxsched_usleep(ODR_TO_INTERVAL[dev->odr]);
     }
 
   sninfo("LIS2MDL self-test samples complete.");
@@ -1222,7 +1222,7 @@ static int lis2mdl_thread(int argc, char **argv)
 
       /* Wait for next measurement cycle */
 
-      nxsig_usleep(ODR_TO_INTERVAL[dev->odr]);
+      nxsched_usleep(ODR_TO_INTERVAL[dev->odr]);
     }
 
   return err;
diff --git a/drivers/sensors/lsm303agr.c b/drivers/sensors/lsm303agr.c
index c768baa6417..9e380798cd1 100644
--- a/drivers/sensors/lsm303agr.c
+++ b/drivers/sensors/lsm303agr.c
@@ -510,7 +510,7 @@ static int lsm303agr_selftest(FAR struct lsm303agr_dev_s *priv,
       g_magnetofactor = 1;
     }
 
-  nxsig_usleep(100000);         /* 100ms */
+  nxsched_usleep(100000);         /* 100ms */
 
   /* Read the output registers after checking XLDA bit 5 times */
 
@@ -532,7 +532,7 @@ static int lsm303agr_selftest(FAR struct lsm303agr_dev_s *priv,
         }
     }
 
-  nxsig_usleep(100000);         /* 100ms */
+  nxsched_usleep(100000);         /* 100ms */
 
   /* Read OUT registers Gyro is starting at 22h and Accelero at 28h */
 
@@ -618,7 +618,7 @@ static int lsm303agr_selftest(FAR struct lsm303agr_dev_s *priv,
       lsm303agr_writereg8(priv, LSM303AGR_CFG_REG_C_M, 0x12);
     }
 
-  nxsig_usleep(100000);         /* 100ms */
+  nxsched_usleep(100000);         /* 100ms */
 
   checkbit = false;
   while (checkbit)
@@ -635,7 +635,7 @@ static int lsm303agr_selftest(FAR struct lsm303agr_dev_s *priv,
         }
     }
 
-  nxsig_usleep(100000);    /* 100ms */
+  nxsched_usleep(100000);    /* 100ms */
 
   /* Now do all the ST values */
 
@@ -673,7 +673,7 @@ static int lsm303agr_selftest(FAR struct lsm303agr_dev_s *priv,
           checkbit = lsm303agr_isbitset(value, LSM303AGR_STATUS_REG_M_ZYXDA);
         }
 
-      nxsig_usleep(100000);    /* 100ms */
+      nxsched_usleep(100000);    /* 100ms */
 
       lsm303agr_readreg8(priv,
                          LSM303AGR_OUT_X_L_A + registershift,
@@ -812,7 +812,7 @@ static int lsm303agr_selftest(FAR struct lsm303agr_dev_s *priv,
       sninfo("\n");
     }
 
-  nxsig_sleep(2);
+  nxsched_sleep(2);
 
   /* Disable test */
 
diff --git a/drivers/sensors/lsm6dsl.c b/drivers/sensors/lsm6dsl.c
index 7250e2c91c9..501b01f2261 100644
--- a/drivers/sensors/lsm6dsl.c
+++ b/drivers/sensors/lsm6dsl.c
@@ -526,7 +526,7 @@ static int lsm6dsl_selftest(FAR struct lsm6dsl_dev_s *priv, uint32_t mode)
   lsm6dsl_writereg8(priv, LSM6DSL_CTRL9_XL, 0x00);
   lsm6dsl_writereg8(priv, LSM6DSL_CTRL10_C, 0x00);
 
-  nxsig_usleep(100000);         /* 100ms */
+  nxsched_usleep(100000);         /* 100ms */
 
   /* Read the output registers after checking XLDA bit 5 times */
 
@@ -547,7 +547,7 @@ static int lsm6dsl_selftest(FAR struct lsm6dsl_dev_s *priv, uint32_t mode)
         }
     }
 
-  nxsig_usleep(100000);    /* 100ms */
+  nxsched_usleep(100000);    /* 100ms */
 
   /* Read OUT registers Gyro is starting at 22h and Accelero at 28h */
 
@@ -632,7 +632,7 @@ static int lsm6dsl_selftest(FAR struct lsm6dsl_dev_s *priv, uint32_t mode)
       lsm6dsl_writereg8(priv, LSM6DSL_CTRL5_C, 0x04);
     }
 
-  nxsig_usleep(100000);         /* 100ms */
+  nxsched_usleep(100000);         /* 100ms */
 
   checkbit = false;
   while (checkbit)              /* wait until first sample and data is
@@ -649,7 +649,7 @@ static int lsm6dsl_selftest(FAR struct lsm6dsl_dev_s *priv, uint32_t mode)
         }
     }
 
-  nxsig_usleep(100000);         /* 100ms */
+  nxsched_usleep(100000);         /* 100ms */
 
   /* Now do all the ST values */
 
@@ -686,7 +686,7 @@ static int lsm6dsl_selftest(FAR struct lsm6dsl_dev_s *priv, uint32_t mode)
           checkbit = lsm6dsl_isbitset(value, LSM6DSL_STATUS_REG_GDA);
         }
 
-      nxsig_usleep(100000);     /* 100ms */
+      nxsched_usleep(100000);     /* 100ms */
 
       lsm6dsl_readreg8(priv,
                        LSM6DSL_OUTX_L_G + registershift,
@@ -794,7 +794,7 @@ static int lsm6dsl_selftest(FAR struct lsm6dsl_dev_s *priv, uint32_t mode)
       sninfo("\n");
     }
 
-  nxsig_sleep(2);
+  nxsched_sleep(2);
 
   /* Disable test */
 
diff --git a/drivers/sensors/lsm6dso32_uorb.c b/drivers/sensors/lsm6dso32_uorb.c
index b15ca60e716..4220c523c3b 100644
--- a/drivers/sensors/lsm6dso32_uorb.c
+++ b/drivers/sensors/lsm6dso32_uorb.c
@@ -847,7 +847,7 @@ static int gyro_thread(int argc, char **argv)
 
       /* Wait for next measurement cycle */
 
-      nxsig_usleep(ODR_INTERVAL[dev->gyro.odr]);
+      nxsched_usleep(ODR_INTERVAL[dev->gyro.odr]);
     }
 
   return err;
@@ -890,7 +890,7 @@ static int accel_thread(int argc, char **argv)
 
       /* Wait for next measurement cycle */
 
-      nxsig_usleep(ODR_INTERVAL[dev->accel.odr]);
+      nxsched_usleep(ODR_INTERVAL[dev->accel.odr]);
     }
 
   return err;
@@ -1036,7 +1036,7 @@ static int gyro_selftest(FAR struct lsm6dso32_dev_s *dev)
 
   /* Wait for 100ms for stable output */
 
-  nxsig_usleep(100000);
+  nxsched_usleep(100000);
 
   /* Discard first measurement */
 
@@ -1089,7 +1089,7 @@ static int gyro_selftest(FAR struct lsm6dso32_dev_s *dev)
 
   /* Wait 100ms for stable output */
 
-  nxsig_usleep(100000);
+  nxsched_usleep(100000);
 
   /* Discard first measurement */
 
@@ -1167,7 +1167,7 @@ static int gyro_selftest(FAR struct lsm6dso32_dev_s *dev)
       goto early_restore;
     }
 
-  nxsig_usleep(100000);
+  nxsched_usleep(100000);
 
 early_restore:
 
@@ -1186,7 +1186,7 @@ early_restore:
             err);
     }
 
-  nxsig_usleep(100000);
+  nxsched_usleep(100000);
 
 early_ret:
   nxmutex_unlock(&dev->devlock);
@@ -1251,7 +1251,7 @@ static int accel_selftest(FAR struct lsm6dso32_dev_s *dev)
 
   /* Wait for 100ms for stable output */
 
-  nxsig_usleep(100000);
+  nxsched_usleep(100000);
 
   /* Discard first measurement */
 
@@ -1305,7 +1305,7 @@ static int accel_selftest(FAR struct lsm6dso32_dev_s *dev)
 
   /* Wait 100ms for stable output */
 
-  nxsig_usleep(100000);
+  nxsched_usleep(100000);
 
   /* Discard first measurement */
 
@@ -1384,7 +1384,7 @@ static int accel_selftest(FAR struct lsm6dso32_dev_s *dev)
       goto early_restore;
     }
 
-  nxsig_usleep(100000);
+  nxsched_usleep(100000);
 
 early_restore:
 
diff --git a/drivers/sensors/lsm9ds1_uorb.c b/drivers/sensors/lsm9ds1_uorb.c
index db32087fbe5..70ac95191b8 100644
--- a/drivers/sensors/lsm9ds1_uorb.c
+++ b/drivers/sensors/lsm9ds1_uorb.c
@@ -650,7 +650,7 @@ static int lsm9ds1_thread(int argc, FAR char **argv)
 
       min_interval = MIN(accel->interval, gyro->interval);
       min_interval = MIN(min_interval, mag->interval);
-      nxsig_usleep(min_interval);
+      nxsched_usleep(min_interval);
     }
 
   return OK;
diff --git a/drivers/sensors/ltr308_uorb.c b/drivers/sensors/ltr308_uorb.c
index d5ca0d865ff..90d52d6a1fc 100644
--- a/drivers/sensors/ltr308_uorb.c
+++ b/drivers/sensors/ltr308_uorb.c
@@ -569,7 +569,7 @@ static int ltr308_thread(int argc, char** argv)
                                  sizeof(struct sensor_light));
 
 thread_sleep:
-      nxsig_usleep(CONFIG_SENSORS_LTR308_POLL_INTERVAL);
+      nxsched_usleep(CONFIG_SENSORS_LTR308_POLL_INTERVAL);
     }
 
   return OK;
diff --git a/drivers/sensors/mcp9600_uorb.c b/drivers/sensors/mcp9600_uorb.c
index 02f999052fe..beafed9f2d3 100644
--- a/drivers/sensors/mcp9600_uorb.c
+++ b/drivers/sensors/mcp9600_uorb.c
@@ -800,7 +800,7 @@ static int mcp9600_thread(int argc, char **argv)
 
       /* Sleep before next fetch */
 
-      nxsig_usleep(dev->interval);
+      nxsched_usleep(dev->interval);
     }
 
   return OK;
diff --git a/drivers/sensors/mlx90614.c b/drivers/sensors/mlx90614.c
index 7e861c52266..8b3cca3665f 100644
--- a/drivers/sensors/mlx90614.c
+++ b/drivers/sensors/mlx90614.c
@@ -215,7 +215,7 @@ static int mlx90614_write_word(FAR struct mlx90614_dev_s *priv, uint8_t cmd,
 
   /* Wait the EEPROM erase */
 
-  nxsig_usleep(10 * 1000);
+  nxsched_usleep(10 * 1000);
 
   /* Create the I2C command that will be sent to device */
 
diff --git a/drivers/sensors/mpl115a.c b/drivers/sensors/mpl115a.c
index 0fbd21b3450..af4065d76e2 100644
--- a/drivers/sensors/mpl115a.c
+++ b/drivers/sensors/mpl115a.c
@@ -206,7 +206,7 @@ static void mpl115a_read_press_temp(FAR struct mpl115a_dev_s *priv)
 
   /* Delay 5ms */
 
-  nxsig_usleep(5000);
+  nxsched_usleep(5000);
 
   priv->mpl115a_pressure =
     mpl115a_getreg8(priv, MPL115A_BASE_CMD | (MPL115A_PADC_MSB << 1)) << 8;
diff --git a/drivers/sensors/mpu60x0.c b/drivers/sensors/mpu60x0.c
index d7d8549ffbc..bd26f49b51d 100644
--- a/drivers/sensors/mpu60x0.c
+++ b/drivers/sensors/mpu60x0.c
@@ -787,19 +787,19 @@ static int mpu_reset(FAR struct mpu_dev_s *dev)
 
   do
     {
-      nxsig_usleep(50000);            /* usecs (arbitrary) */
+      nxsched_usleep(50000);            /* usecs (arbitrary) */
     }
   while (__mpu_read_pwr_mgmt_1(dev) & PWR_MGMT_1__DEVICE_RESET);
 
   /* Reset signal paths */
 
   __mpu_write_signal_path_reset(dev, SIGNAL_PATH_RESET__ALL_RESET);
-  nxsig_usleep(2000);
+  nxsched_usleep(2000);
 
   /* Disable SLEEP, use PLL with z-axis clock source */
 
   __mpu_write_pwr_mgmt_1(dev, 3);
-  nxsig_usleep(2000);
+  nxsched_usleep(2000);
 
   /* Disable i2c if we're on spi. */
 
diff --git a/drivers/sensors/mpu9250_uorb.c b/drivers/sensors/mpu9250_uorb.c
index ca8e42cd21f..e5bbe22f018 100644
--- a/drivers/sensors/mpu9250_uorb.c
+++ b/drivers/sensors/mpu9250_uorb.c
@@ -1111,7 +1111,7 @@ static int mpu9250_initialize(FAR struct mpu9250_dev_s *dev)
 
   do
     {
-      nxsig_usleep(50000);            /* usecs (arbitrary) */
+      nxsched_usleep(50000);            /* usecs (arbitrary) */
     }
   while (mpu9250_read_pwr_mgmt_1(dev) & PWR_MGMT_1_DEVICE_RESET);
 
@@ -1124,7 +1124,7 @@ static int mpu9250_initialize(FAR struct mpu9250_dev_s *dev)
       goto errout;
     }
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Disable SLEEP, use PLL with z-axis clock source */
 
@@ -1135,7 +1135,7 @@ static int mpu9250_initialize(FAR struct mpu9250_dev_s *dev)
       goto errout;
     }
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Disable low-power mode, enable all gyros and accelerometers */
 
@@ -1146,7 +1146,7 @@ static int mpu9250_initialize(FAR struct mpu9250_dev_s *dev)
       goto errout;
     }
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* clear first, and separate *_RST from *_EN */
 
@@ -1157,7 +1157,7 @@ static int mpu9250_initialize(FAR struct mpu9250_dev_s *dev)
       goto errout;
     }
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   ret = mpu9250_write_fifo_en(dev, 0);
   if (ret < 0)
@@ -1166,7 +1166,7 @@ static int mpu9250_initialize(FAR struct mpu9250_dev_s *dev)
       goto errout;
     }
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Reset I2C Master module. */
 
@@ -1179,7 +1179,7 @@ static int mpu9250_initialize(FAR struct mpu9250_dev_s *dev)
       goto errout;
     }
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Disable i2c if we're on spi. */
 
@@ -1202,7 +1202,7 @@ static int mpu9250_initialize(FAR struct mpu9250_dev_s *dev)
       goto errout;
     }
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* default No FSYNC, set accel LPF at 184 Hz, gyro LPF at 188 Hz in
    * menuconfig
@@ -1216,7 +1216,7 @@ static int mpu9250_initialize(FAR struct mpu9250_dev_s *dev)
       goto errout;
     }
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* default ± 1000 deg/sec in menuconfig */
 
@@ -1227,7 +1227,7 @@ static int mpu9250_initialize(FAR struct mpu9250_dev_s *dev)
       goto errout;
     }
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* default ± 8g in menuconfig */
 
@@ -1238,7 +1238,7 @@ static int mpu9250_initialize(FAR struct mpu9250_dev_s *dev)
       goto errout;
     }
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Accelerometer low pass filter setting */
 
@@ -1250,7 +1250,7 @@ static int mpu9250_initialize(FAR struct mpu9250_dev_s *dev)
       goto errout;
     }
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* clear INT on any read (we aren't using that pin right now) */
 
@@ -1261,7 +1261,7 @@ static int mpu9250_initialize(FAR struct mpu9250_dev_s *dev)
       goto errout;
     }
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Initialize ak8963 magnetometer inside the IMU */
 
@@ -1317,7 +1317,7 @@ static int ak8963_initialize(FAR struct mpu9250_dev_s *dev,
       return ret;
     }
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* First set power-down mode */
 
@@ -1334,7 +1334,7 @@ static int ak8963_initialize(FAR struct mpu9250_dev_s *dev,
       return ret;
     }
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* get mag version ID */
 
@@ -1372,7 +1372,7 @@ static int ak8963_initialize(FAR struct mpu9250_dev_s *dev,
       return ret;
     }
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Slave 0 provides ST1, mag data, and ST2 data in a bulk transfer of
    * 8 bytes of data.  Use the address of ST1 in SLV0_REG as the beginning
@@ -1403,7 +1403,7 @@ static int ak8963_initialize(FAR struct mpu9250_dev_s *dev,
       return ret;
     }
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Enable reading of the mag every n samples, dividing down from the
    * output data rate provided by the caller.
@@ -1417,7 +1417,7 @@ static int ak8963_initialize(FAR struct mpu9250_dev_s *dev,
       return ret;
     }
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   /* Enable delayed I2C transfers for the mag on Slave 0 registers. */
 
@@ -1429,7 +1429,7 @@ static int ak8963_initialize(FAR struct mpu9250_dev_s *dev,
       return ret;
     }
 
-  nxsig_usleep(1000);
+  nxsched_usleep(1000);
 
   return 0;
 }
@@ -1463,7 +1463,7 @@ static int get_mag_adjustment(FAR struct mpu9250_dev_s *dev)
       return ret;
     }
 
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
 
   /* Enable FUSE ROM, since the sensitivity adjustment data is stored in
    * compass registers 0x10, 0x11 and 0x12 which is only accessible in Fuse
@@ -1477,7 +1477,7 @@ static int get_mag_adjustment(FAR struct mpu9250_dev_s *dev)
       return ret;
     }
 
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
 
   /* Get compass calibration register 0x10, 0x11, 0x12 store into context */
 
@@ -1506,7 +1506,7 @@ static int get_mag_adjustment(FAR struct mpu9250_dev_s *dev)
       return ret;
     }
 
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
 
   return 0;
 }
@@ -1578,7 +1578,7 @@ static int read_ak8963_reg(FAR struct mpu9250_dev_s *dev,
 
   do
     {
-      nxsig_usleep(1000);
+      nxsched_usleep(1000);
       ret = mpu9250_read_reg(dev, I2C_MST_STATUS,  &b, sizeof(b));
       if (ret < 0)
         {
@@ -1681,7 +1681,7 @@ static int write_ak8963_reg(FAR struct mpu9250_dev_s *dev,
 
   do
     {
-      nxsig_usleep(1000);
+      nxsched_usleep(1000);
       ret = mpu9250_read_reg(dev, I2C_MST_STATUS, &b, sizeof(b));
       if (ret < 0)
         {
@@ -1915,7 +1915,7 @@ static int mpu9250_thread(int argc, FAR char **argv)
 
       min_interval = MIN(accel->interval, gyro->interval);
       min_interval = MIN(min_interval, mag->interval);
-      nxsig_usleep(min_interval);
+      nxsched_usleep(min_interval);
     }
 
   return OK;
diff --git a/drivers/sensors/ms56xx_uorb.c b/drivers/sensors/ms56xx_uorb.c
index a659c7e347f..359fccc6cae 100644
--- a/drivers/sensors/ms56xx_uorb.c
+++ b/drivers/sensors/ms56xx_uorb.c
@@ -266,7 +266,7 @@ static inline void baro_measure_read(FAR struct ms56xx_dev_s *priv,
 
   /* Wait data acquisition */
 
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
 
   /* Send command to start a read sequence */
 
@@ -303,7 +303,7 @@ static inline void baro_measure_read(FAR struct ms56xx_dev_s *priv,
 
   /* Wait data acquisition */
 
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
 
   /* Send command to start a read sequence */
 
@@ -384,7 +384,7 @@ static int ms56xx_thread(int argc, char **argv)
 
       /* Sleeping thread before fetching the next sensor data */
 
-      nxsig_usleep(priv->interval);
+      nxsched_usleep(priv->interval);
     }
 
   return OK;
@@ -417,7 +417,7 @@ static int ms56xx_initialize(FAR struct ms56xx_dev_s *priv)
 
   /* We have to wait before the prom is ready is be read */
 
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
 
   for (i = 0; i < 8; i++)
     {
diff --git a/drivers/sensors/nau7802.c b/drivers/sensors/nau7802.c
index 42b1c18b232..08d4102e9a1 100644
--- a/drivers/sensors/nau7802.c
+++ b/drivers/sensors/nau7802.c
@@ -875,7 +875,7 @@ static int nau7802_thread(int argc, FAR char *argv[])
 
       /* Wait for next measurement cycle */
 
-      nxsig_usleep(dev->interval);
+      nxsched_usleep(dev->interval);
     }
 
   return err;
diff --git a/drivers/sensors/scd30.c b/drivers/sensors/scd30.c
index d6d7b14fc85..4ef4ad9f317 100644
--- a/drivers/sensors/scd30.c
+++ b/drivers/sensors/scd30.c
@@ -486,11 +486,7 @@ static int scd30_read_values(FAR struct scd30_dev_s *priv, FAR float *temp,
                   return ret;
                 }
 
-              ret = nxsig_usleep(500 * 1000);
-              if (ret == -EINTR)
-                {
-                  return ret;
-                }
+              nxsched_usleep(500 * 1000);
             }
           else
             {
diff --git a/drivers/sensors/scd41.c b/drivers/sensors/scd41.c
index 71079454597..e94e6361558 100644
--- a/drivers/sensors/scd41.c
+++ b/drivers/sensors/scd41.c
@@ -476,11 +476,7 @@ static int scd41_read_values(FAR struct scd41_dev_s *priv, FAR float *temp,
                   return ret;
                 }
 
-              ret = nxsig_usleep(500 * 1000);
-              if (ret == -EINTR)
-                {
-                  return ret;
-                }
+              nxsched_usleep(500 * 1000);
             }
           else
             {
diff --git a/drivers/sensors/sgp30.c b/drivers/sensors/sgp30.c
index 938589d1837..b23f8043d42 100644
--- a/drivers/sensors/sgp30.c
+++ b/drivers/sensors/sgp30.c
@@ -628,7 +628,7 @@ static int sgp30_open(FAR struct file *filep)
                       return ret;
                     }
 
-                  nxsig_usleep(CONFIG_SGP30_RESET_DELAY_US);
+                  nxsched_usleep(CONFIG_SGP30_RESET_DELAY_US);
 
                   clock_systime_timespec(&start);
                   ret = sgp30_write_cmd(priv, SGP30_CMD_INIT_AIR_QUALITY,
diff --git a/drivers/sensors/sht4x_uorb.c b/drivers/sensors/sht4x_uorb.c
index 302d72c100c..9ac0cecdcf3 100644
--- a/drivers/sensors/sht4x_uorb.c
+++ b/drivers/sensors/sht4x_uorb.c
@@ -784,7 +784,7 @@ static int sht4x_thread(int argc, char **argv)
 
       /* Sleep before next fetch */
 
-      nxsig_usleep(dev->interval);
+      nxsched_usleep(dev->interval);
     }
 
   return OK;
diff --git a/drivers/sensors/sps30.c b/drivers/sensors/sps30.c
index 432bfa58791..4cdaa7018e5 100644
--- a/drivers/sensors/sps30.c
+++ b/drivers/sensors/sps30.c
@@ -490,11 +490,7 @@ static int sps30_read_values(FAR struct sps30_dev_s *priv,
                   return ret;
                 }
 
-              ret = nxsig_usleep(500 * 1000);
-              if (ret == -EINTR)
-                {
-                  return ret;
-                }
+              nxsched_usleep(500 * 1000);
             }
           else
             {
diff --git a/drivers/sensors/tmp112.c b/drivers/sensors/tmp112.c
index 6cf70658252..0da66013a70 100644
--- a/drivers/sensors/tmp112.c
+++ b/drivers/sensors/tmp112.c
@@ -107,7 +107,7 @@ static uint16_t tmp112_getreg16(FAR struct tmp112_dev_s *priv,
 
   if (ms_delay > 0)
     {
-      nxsig_usleep(ms_delay * 1000);
+      nxsched_usleep(ms_delay * 1000);
     }
 
   /* Read register */
diff --git a/drivers/sensors/veml6070.c b/drivers/sensors/veml6070.c
index 279779b3305..fad1aab0af5 100644
--- a/drivers/sensors/veml6070.c
+++ b/drivers/sensors/veml6070.c
@@ -193,7 +193,7 @@ static ssize_t veml6070_read(FAR struct file *filep, FAR char *buffer,
 
   /* 1T for Rset 270Kohms is 125ms */
 
-  nxsig_usleep(125000);
+  nxsched_usleep(125000);
 
   /* Read the MSB first */
 
diff --git a/drivers/sensors/wtgahrs2_uorb.c b/drivers/sensors/wtgahrs2_uorb.c
index 2463a92d5de..c72b9db5bfa 100644
--- a/drivers/sensors/wtgahrs2_uorb.c
+++ b/drivers/sensors/wtgahrs2_uorb.c
@@ -148,7 +148,7 @@ static void wtgahrs2_sendcmd(FAR struct wtgahrs2_dev_s *rtdata,
                              const void *cmd)
 {
   file_write(&rtdata->file, cmd, WTGAHRS2_CMD_LENGTH);
-  nxsig_usleep(10000);
+  nxsched_usleep(10000);
 }
 
 static int wtgahrs2_activate(FAR struct sensor_lowerhalf_s *lower,
diff --git a/drivers/serial/serial.c b/drivers/serial/serial.c
index f5aaec1953f..8cfece7efa7 100644
--- a/drivers/serial/serial.c
+++ b/drivers/serial/serial.c
@@ -596,7 +596,7 @@ static int uart_tcdrain(FAR uart_dev_t *dev,
             {
               clock_t elapsed;
 
-              nxsig_usleep(POLL_DELAY_USEC);
+              nxsched_usleep(POLL_DELAY_USEC);
 
               /* Check for a timeout */
 
@@ -666,7 +666,7 @@ static int uart_tcsendbreak(FAR uart_dev_t *dev, FAR struct file *filep,
             {
               /* Wait 400 ms or the requested Break duration */
 
-              nxsig_usleep((ms == 0) ? 400000 : ms * 1000);
+              nxsched_usleep((ms == 0) ? 400000 : ms * 1000);
 
               /* Request lower half driver to end the Break */
 
diff --git a/drivers/spi/spi_transfer.c b/drivers/spi/spi_transfer.c
index c99a5541952..12ffa3527b6 100644
--- a/drivers/spi/spi_transfer.c
+++ b/drivers/spi/spi_transfer.c
@@ -134,7 +134,7 @@ int spi_transfer(FAR struct spi_dev_s *spi, FAR struct spi_sequence_s *seq)
 
       if (trans->delay > 0)
         {
-          nxsig_usleep(trans->delay);
+          nxsched_usleep(trans->delay);
         }
     }
 
diff --git a/drivers/timers/mcp794xx.c b/drivers/timers/mcp794xx.c
index 4cb4ce9b2d4..6308b80395b 100644
--- a/drivers/timers/mcp794xx.c
+++ b/drivers/timers/mcp794xx.c
@@ -570,7 +570,7 @@ int up_rtc_settime(FAR const struct timespec *tp)
     {
       /* Give time to oscillator to change its status */
 
-      nxsig_usleep(10000);
+      nxsched_usleep(10000);
 
       ret = I2C_TRANSFER(g_mcp794xx.i2c, msg, 2);
       if (ret < 0)
@@ -674,7 +674,7 @@ int up_rtc_settime(FAR const struct timespec *tp)
     {
       /* Give time to oscillator to change its status */
 
-      nxsig_usleep(10000);
+      nxsched_usleep(10000);
 
       ret = I2C_TRANSFER(g_mcp794xx.i2c, msg, 2);
       if (ret < 0)
diff --git a/drivers/usbdev/usbmsc_scsi.c b/drivers/usbdev/usbmsc_scsi.c
index 4e98c1b2acf..83b60cccae9 100644
--- a/drivers/usbdev/usbmsc_scsi.c
+++ b/drivers/usbdev/usbmsc_scsi.c
@@ -2657,12 +2657,12 @@ static int usbmsc_cmdfinishstate(FAR struct usbmsc_dev_s *priv)
                * endpoint
                */
 
-              nxsig_usleep (100000);
+              nxsched_usleep (100000);
               EP_STALL(priv->epbulkin);
 
               /* now wait for stall to go away .... */
 
-              nxsig_usleep (100000);
+              nxsched_usleep (100000);
 #else
               EP_STALL(priv->epbulkin);
 #endif
diff --git a/drivers/usbhost/usbhost_enumerate.c b/drivers/usbhost/usbhost_enumerate.c
index f74875b2d3a..c292ad015ec 100644
--- a/drivers/usbhost/usbhost_enumerate.c
+++ b/drivers/usbhost/usbhost_enumerate.c
@@ -428,7 +428,7 @@ int usbhost_enumerate(FAR struct usbhost_hubport_s *hport,
       goto errout;
     }
 
-  nxsig_usleep(2 * 1000);
+  nxsched_usleep(2 * 1000);
 
   /* Assign the function address to the port */
 
@@ -509,7 +509,7 @@ int usbhost_enumerate(FAR struct usbhost_hubport_s *hport,
 
   /* Some devices may require some delay before initialization */
 
-  nxsig_usleep(100 * 1000);
+  nxsched_usleep(100 * 1000);
 
   /* Was the class identification information provided in the device
    * descriptor? Or do we need to find it in the interface descriptor(s)?
diff --git a/drivers/usbhost/usbhost_hidkbd.c b/drivers/usbhost/usbhost_hidkbd.c
index f7269522b38..814447d14e4 100644
--- a/drivers/usbhost/usbhost_hidkbd.c
+++ b/drivers/usbhost/usbhost_hidkbd.c
@@ -1398,7 +1398,7 @@ static int usbhost_kbdpoll(int argc, FAR char *argv[])
 
   priv->polling = true;
   nxsem_post(&priv->syncsem);
-  nxsig_sleep(1);
+  nxsched_sleep(1);
 
   /* Loop here until the device is disconnected */
 
@@ -1532,7 +1532,7 @@ static int usbhost_kbdpoll(int argc, FAR char *argv[])
           delay = CONFIG_HIDKBD_POLLUSEC;
         }
 
-      nxsig_usleep(delay);
+      nxsched_usleep(delay);
     }
 
   /* We get here when the driver is removed.. or when too many errors have
diff --git a/drivers/usbhost/usbhost_hidmouse.c b/drivers/usbhost/usbhost_hidmouse.c
index 1dc61a8eb31..9c7324aa965 100644
--- a/drivers/usbhost/usbhost_hidmouse.c
+++ b/drivers/usbhost/usbhost_hidmouse.c
@@ -975,7 +975,7 @@ static int usbhost_mouse_poll(int argc, FAR char *argv[])
 
   priv->polling = true;
   nxsem_post(&g_syncsem);
-  nxsig_sleep(1);
+  nxsched_sleep(1);
 
   /* Loop here until the device is disconnected */
 
diff --git a/drivers/usbhost/usbhost_hub.c b/drivers/usbhost/usbhost_hub.c
index ee642fbeffc..b87f15be602 100644
--- a/drivers/usbhost/usbhost_hub.c
+++ b/drivers/usbhost/usbhost_hub.c
@@ -870,7 +870,7 @@ static void usbhost_hub_event(FAR void *arg)
                 }
 
               debouncetime += 25;
-              nxsig_usleep(25 * 1000);
+              nxsched_usleep(25 * 1000);
             }
 
           if (ret < 0 || debouncetime >= 1500)
@@ -898,7 +898,7 @@ static void usbhost_hub_event(FAR void *arg)
                   continue;
                 }
 
-              nxsig_usleep(100 * 1000);
+              nxsched_usleep(100 * 1000);
 
               ctrlreq->type = USB_REQ_DIR_IN | USBHUB_REQ_TYPE_PORT;
               ctrlreq->req  = USBHUB_REQ_GETSTATUS;
diff --git a/drivers/usbhost/usbhost_max3421e.c b/drivers/usbhost/usbhost_max3421e.c
index 5b42abd5878..e0c162d3b87 100644
--- a/drivers/usbhost/usbhost_max3421e.c
+++ b/drivers/usbhost/usbhost_max3421e.c
@@ -1827,7 +1827,7 @@ static ssize_t max3421e_out_transfer(FAR struct max3421e_usbhost_s *priv,
            * transfer using the same buffer pointer and length.
            */
 
-          nxsig_usleep(20 * 1000);
+          nxsched_usleep(20 * 1000);
         }
       else
         {
@@ -2715,9 +2715,9 @@ static ssize_t max3421e_in_transfer(FAR struct max3421e_usbhost_s *priv,
                    *
                    * Small delays could require more resolution than is
                    * provided by the system timer.  For example, if the
-                   * system timer resolution is 10MS, then nxsig_usleep(1000)
-                   * will actually request a delay 20MS (due to both
-                   * quantization and rounding).
+                   * system timer resolution is 10MS, then
+                   * nxsched_usleep(1000) will actually request a delay
+                   * 20MS (due to both quantization and rounding).
                    *
                    * REVISIT: So which is better?  To ignore tiny delays and
                    * hog the system bandwidth?  Or to wait for an excessive
@@ -2726,7 +2726,7 @@ static ssize_t max3421e_in_transfer(FAR struct max3421e_usbhost_s *priv,
 
                   if (delay > CONFIG_USEC_PER_TICK)
                     {
-                      nxsig_usleep(delay - CONFIG_USEC_PER_TICK);
+                      nxsched_usleep(delay - CONFIG_USEC_PER_TICK);
                     }
                 }
             }
@@ -2967,7 +2967,7 @@ static int max3421e_connected(FAR struct max3421e_usbhost_s *priv)
   /* Stop SOF generation and reset the bus */
 
   max3421e_busreset(priv);
-  nxsig_sleep(1);
+  nxsched_sleep(1);
 
   /* Check for low- or full-speed and restart SOF generation. */
 
@@ -3261,7 +3261,7 @@ static void max3421e_int_wait(FAR struct max3421e_usbhost_s *priv,
 
       if (regval == 0 && usec > 0)
         {
-          nxsig_usleep(usec);
+          nxsched_usleep(usec);
         }
     }
   while (regval == 0);
@@ -3419,7 +3419,7 @@ static int max3421e_getspeed(FAR struct max3421e_usbhost_s *priv,
    * 100ms.
    */
 
-  nxsig_usleep(100 * 1000);
+  nxsched_usleep(100 * 1000);
 
   /* Make sure we are still connected */
 
@@ -3435,7 +3435,7 @@ static int max3421e_getspeed(FAR struct max3421e_usbhost_s *priv,
   /* Stop SOF generation and reset the host port */
 
   max3421e_busreset(priv);
-  nxsig_sleep(1);
+  nxsched_sleep(1);
 
   /* Get the current device speed */
 
@@ -4548,7 +4548,7 @@ static int max3421e_startsof(FAR struct max3421e_usbhost_s *priv)
   while ((max3421e_getreg(priv, MAX3421E_USBHOST_HCTL) &
           USBHOST_HCTL_BUSSAMPLE) == 0)
     {
-      nxsig_usleep(5);
+      nxsched_usleep(5);
     }
 
   /* Check for low- or full-speed and start SOF (actually already started
@@ -4622,7 +4622,7 @@ static int max3421e_startsof(FAR struct max3421e_usbhost_s *priv)
   /* Wait for the first SOF received and 20ms has passed */
 
   max3421e_int_wait(priv, USBHOST_HIRQ_FRAMEIRQ, 0);
-  nxsig_usleep(20 * 1000);
+  nxsched_usleep(20 * 1000);
   return OK;
 }
 
diff --git a/drivers/usbhost/usbhost_storage.c b/drivers/usbhost/usbhost_storage.c
index 45cae2de110..f4de798c78a 100644
--- a/drivers/usbhost/usbhost_storage.c
+++ b/drivers/usbhost/usbhost_storage.c
@@ -1227,7 +1227,7 @@ static inline int usbhost_initvolume(FAR struct usbhost_state_s *priv)
 
       /* Wait just a bit */
 
-      nxsig_usleep(USBHOST_RETRY_USEC);
+      nxsched_usleep(USBHOST_RETRY_USEC);
 
       /* Send TESTUNITREADY to see if the unit is ready.  The most likely
        * error error that can occur here is a a stall which simply means
diff --git a/drivers/usbhost/usbhost_xboxcontroller.c b/drivers/usbhost/usbhost_xboxcontroller.c
index a9689197c81..76029e178ad 100644
--- a/drivers/usbhost/usbhost_xboxcontroller.c
+++ b/drivers/usbhost/usbhost_xboxcontroller.c
@@ -570,7 +570,7 @@ static int usbhost_xboxcontroller_poll(int argc, FAR char *argv[])
 
   priv->polling = true;
   nxsem_post(&g_syncsem);
-  nxsig_sleep(1);
+  nxsched_sleep(1);
 
   /* Loop here until the device is disconnected */
 
diff --git a/drivers/usbmisc/fusb302.c b/drivers/usbmisc/fusb302.c
index f0c27cc59bb..d3695b518ef 100644
--- a/drivers/usbmisc/fusb302.c
+++ b/drivers/usbmisc/fusb302.c
@@ -648,7 +648,7 @@ void setmdac(struct fusb302_dev_s *priv, enum src_current_e thresh)
   regval |= MEASURE_MDAC(src_mdac_val[thresh]);
 
   fusb302_putreg(priv, FUSB302_MEASURE_REG, regval);
-  nxsig_usleep(150);
+  nxsched_usleep(150);
 }
 
 /****************************************************************************
diff --git a/drivers/usbmonitor/usbmonitor.c b/drivers/usbmonitor/usbmonitor.c
index b9c0da75ec1..a797493d3b2 100644
--- a/drivers/usbmonitor/usbmonitor.c
+++ b/drivers/usbmonitor/usbmonitor.c
@@ -154,7 +154,7 @@ static int usbmonitor_daemon(int argc, FAR char **argv)
 
   while (!g_usbmonitor.stop)
     {
-      nxsig_sleep(CONFIG_USBMONITOR_INTERVAL);
+      nxsched_sleep(CONFIG_USBMONITOR_INTERVAL);
 #ifdef CONFIG_USBDEV_TRACE
       usbtrace_enumerate(usbmonitor_tracecallback, NULL);
 #endif
diff --git a/drivers/video/fb.c b/drivers/video/fb.c
index 1e3c0e65761..84092ace835 100644
--- a/drivers/video/fb.c
+++ b/drivers/video/fb.c
@@ -2007,7 +2007,7 @@ int fb_register_device(int display, int plane,
 
   if (SPLASH_SLEEP != 0)
     {
-      nxsig_sleep(SPLASH_SLEEP);
+      nxsched_sleep(SPLASH_SLEEP);
     }
 
 #  ifdef VIDEO_FB_SPLASHSCREEN_CLR_ON_EXIT
diff --git a/drivers/video/isx012.c b/drivers/video/isx012.c
index 37394cb70ea..8f8da1f0190 100644
--- a/drivers/video/isx012.c
+++ b/drivers/video/isx012.c
@@ -773,7 +773,7 @@ static int isx012_chk_int_state(FAR isx012_dev_t *priv,
   uint8_t data;
   uint32_t time = 0;
 
-  nxsig_usleep(delay_time * 1000);
+  nxsched_usleep(delay_time * 1000);
   while (time < timeout)
     {
       data = isx012_getreg(priv, INTSTS0, sizeof(data));
@@ -784,7 +784,7 @@ static int isx012_chk_int_state(FAR isx012_dev_t *priv,
           return ret;
         }
 
-      nxsig_usleep(wait_time * 1000);
+      nxsched_usleep(wait_time * 1000);
       time += wait_time;
     }
 
@@ -1330,10 +1330,10 @@ int init_isx012(FAR isx012_dev_t *priv)
 #ifdef ISX012_NOT_USE_NSTBY
   board_isx012_release_sleep();
   board_isx012_release_reset();
-  nxsig_usleep(6000);
+  nxsched_usleep(6000);
 #else
   board_isx012_release_reset();
-  nxsig_usleep(6000);
+  nxsched_usleep(6000);
 #endif
 
 #ifdef ISX012_CHECK_IN_DETAIL
diff --git a/drivers/video/isx019.c b/drivers/video/isx019.c
index f26ffef5bdf..c02ce3e8f7a 100644
--- a/drivers/video/isx019.c
+++ b/drivers/video/isx019.c
@@ -1210,14 +1210,14 @@ static int set_drive_mode(FAR isx019_dev_t *priv)
 #endif
     };
 
-  nxsig_usleep(TRANSITION_TIME_TO_STARTUP);
+  nxsched_usleep(TRANSITION_TIME_TO_STARTUP);
 
   isx019_i2c_write(priv, CAT_CONFIG, MODE_SENSSEL,      &drv[INDEX_SENS], 1);
   isx019_i2c_write(priv, CAT_CONFIG, MODE_POSTSEL,      &drv[INDEX_POST], 1);
   isx019_i2c_write(priv,
     CAT_CONFIG, MODE_SENSPOST_SEL, &drv[INDEX_SENSPOST], 1);
 
-  nxsig_usleep(TRANSITION_TIME_TO_STREAMING);
+  nxsched_usleep(TRANSITION_TIME_TO_STREAMING);
 
   return OK;
 }
@@ -2925,7 +2925,7 @@ static int set_jpg_quality(FAR isx019_dev_t *priv,
 
   /* Wait for swap of non-active side and active side. */
 
-  nxsig_usleep(DELAY_TIME_JPEGDQT_SWAP);
+  nxsched_usleep(DELAY_TIME_JPEGDQT_SWAP);
 
   /* Update non-active side in preparation for other activation trigger. */
 
diff --git a/drivers/wireless/bluetooth/bt_uart_bcm4343x.c b/drivers/wireless/bluetooth/bt_uart_bcm4343x.c
index 78622ee0b54..bdb7fd04e69 100644
--- a/drivers/wireless/bluetooth/bt_uart_bcm4343x.c
+++ b/drivers/wireless/bluetooth/bt_uart_bcm4343x.c
@@ -354,7 +354,7 @@ static int load_bcm4343x_firmware(FAR const struct btuart_lowerhalf_s *lower)
 
       /* Give everything time to start up */
 
-      nxsig_usleep(1000000);
+      nxsched_usleep(1000000);
 
       /* Once the firmware has booted it goes back to low speed,
        * so kick it up again
diff --git a/drivers/wireless/cc1101.c b/drivers/wireless/cc1101.c
index 7a936989bb0..dcc366f7356 100644
--- a/drivers/wireless/cc1101.c
+++ b/drivers/wireless/cc1101.c
@@ -661,7 +661,7 @@ void cc1101_access_begin(FAR struct cc1101_dev_s *dev)
     }
   else
     {
-      nxsig_usleep(150 * 1000);
+      nxsched_usleep(150 * 1000);
     }
 }
 
diff --git a/drivers/wireless/gs2200m.c b/drivers/wireless/gs2200m.c
index e982093ea50..51af509e316 100644
--- a/drivers/wireless/gs2200m.c
+++ b/drivers/wireless/gs2200m.c
@@ -867,7 +867,7 @@ retry:
   if (RD_RESP_NOK == res[1])
     {
       wlwarn("*** warning: RD_RESP_NOK received.. retrying. (n=%d)\n", n);
-      nxsig_usleep(100 * 1000);
+      nxsched_usleep(100 * 1000);
       n++;
       goto retry;
     }
@@ -931,7 +931,7 @@ retry:
                      (FAR void *)dev, 0);
         }
 
-      nxsig_usleep(100 * 1000);
+      nxsched_usleep(100 * 1000);
       n++;
       goto retry;
     }
@@ -957,7 +957,7 @@ retry:
     {
       wlwarn("*** warning: 0x%x received.. retrying. (n=%d)\n",
              res[1], n);
-      nxsig_usleep(10 * 1000);
+      nxsched_usleep(10 * 1000);
 
       if (WR_MAX_RETRY < n)
         {
@@ -3220,7 +3220,7 @@ repeat:
 
           while (gs2200m_recv_pkt(dev, NULL) != TYPE_TIMEOUT)
             {
-              nxsig_usleep(100 * 1000);
+              nxsched_usleep(100 * 1000);
             }
         }
       while (gs2200m_ioctl_assoc_sta(dev, &dev->reconnect_msg) != OK);
diff --git a/drivers/wireless/ieee80211/bcm43xxx/bcmf_core.c b/drivers/wireless/ieee80211/bcm43xxx/bcmf_core.c
index 08352049cca..8b321df58a4 100644
--- a/drivers/wireless/ieee80211/bcm43xxx/bcmf_core.c
+++ b/drivers/wireless/ieee80211/bcm43xxx/bcmf_core.c
@@ -569,7 +569,7 @@ int bcmf_core_upload_firmware(FAR bcmf_interface_dev_t *ibus)
         DEBUGPANIC();
     }
 
-  nxsig_usleep(50 * 1000);
+  nxsched_usleep(50 * 1000);
 
   /* Flash chip firmware */
 
@@ -616,12 +616,12 @@ int bcmf_core_upload_firmware(FAR bcmf_interface_dev_t *ibus)
       case SDIO_DEVICE_ID_BROADCOM_43362:
       case SDIO_DEVICE_ID_BROADCOM_43430:
       case SDIO_DEVICE_ID_INFINEON_CYW43439:
-        nxsig_usleep(10 * 1000);
+        nxsched_usleep(10 * 1000);
         bcmf_core_reset(ibus, WLAN_ARMCM3_CORE_ID, 0, 0, 0);
 
         /* Check ARMCM3 core is running */
 
-        nxsig_usleep(10 * 1000);
+        nxsched_usleep(10 * 1000);
         if (!bcmf_core_isup(ibus, WLAN_ARMCM3_CORE_ID))
           {
             wlerr("Cannot start ARMCM3 core\n");
@@ -660,7 +660,7 @@ int bcmf_core_upload_firmware(FAR bcmf_interface_dev_t *ibus)
 
         /* Check ARMCR4 core is running */
 
-        nxsig_usleep(10 * 1000);
+        nxsched_usleep(10 * 1000);
         if (!bcmf_core_isup(ibus, WLAN_ARMCR4_CORE_ID))
           {
             wlerr("Cannot start ARMCR4 core\n");
@@ -729,7 +729,7 @@ void bcmf_core_disable(FAR bcmf_interface_dev_t *ibus,
 
       /*  Ensure no backplane operation is pending */
 
-      nxsig_usleep(10 * 1000);
+      nxsched_usleep(10 * 1000);
 
       bcmf_write_sbregw(ibus,
                         base + BCMA_IOCTL,
diff --git a/drivers/wireless/ieee80211/bcm43xxx/bcmf_driver.c b/drivers/wireless/ieee80211/bcm43xxx/bcmf_driver.c
index 65377ab2752..f8adf12402f 100644
--- a/drivers/wireless/ieee80211/bcm43xxx/bcmf_driver.c
+++ b/drivers/wireless/ieee80211/bcm43xxx/bcmf_driver.c
@@ -1207,7 +1207,7 @@ int bcmf_wl_enable(FAR struct bcmf_dev_s *priv, bool enable)
 
   /* TODO wait for WLC_E_RADIO event */
 
-  nxsig_usleep(3000);
+  nxsched_usleep(3000);
 
   if (ret == OK)
     {
diff --git a/drivers/wireless/ieee80211/bcm43xxx/bcmf_gspi.c b/drivers/wireless/ieee80211/bcm43xxx/bcmf_gspi.c
index 2c94554d3b6..600b05e8a3b 100644
--- a/drivers/wireless/ieee80211/bcm43xxx/bcmf_gspi.c
+++ b/drivers/wireless/ieee80211/bcm43xxx/bcmf_gspi.c
@@ -207,7 +207,7 @@ static int bcmf_gspi_kso_enable(FAR bcmf_gspi_dev_t *gbus, bool enable)
                                   SBSDIO_FUNC1_SLEEPCSR_KSO_MASK
                                 | SBSDIO_FUNC1_SLEEPCSR_DEVON_MASK);
 
-          nxsig_usleep(100 * 1000);
+          nxsched_usleep(100 * 1000);
 
           value = bcmf_gspi_read_reg_8(gspi, 1, SBSDIO_FUNC1_SLEEPCSR);
 
@@ -286,7 +286,7 @@ static int bcmf_gspi_bus_sleep(FAR bcmf_gspi_dev_t *gbus, bool sleep)
 
           /* Wait for High Throughput clock */
 
-          nxsig_usleep(100 * 1000);
+          nxsched_usleep(100 * 1000);
           value = bcmf_gspi_read_reg_8(gspi, 1, SBSDIO_FUNC1_CHIPCLKCSR);
 
           if (value & SBSDIO_HT_AVAIL)
@@ -367,7 +367,7 @@ static int bcmf_gspi_thread(int argc, FAR char **argv)
 
   wlinfo(">>>> entered\n");
 
-  nxsig_usleep(50 * 1000);
+  nxsched_usleep(50 * 1000);
 
   gbus->thread_run = true;
 
@@ -467,7 +467,7 @@ static int bcmf_gspi_thread(int argc, FAR char **argv)
 #ifdef CONFIG_DEBUG_WIRELESS_ERROR
                   wlerr("error sending f2 frame: %d\n", ret);
 #endif
-                  nxsig_usleep(10 * 1000);
+                  nxsched_usleep(10 * 1000);
                 }
             }
         }
@@ -675,7 +675,7 @@ static int bcmf_gspi_init_alp_clock(FAR bcmf_gspi_dev_t *gbus)
   loops = 10;
   while (--loops > 0)
     {
-      nxsig_usleep(10 * 1000);
+      nxsched_usleep(10 * 1000);
 
       value = bcmf_gspi_read_reg_8(gspi,
                                    gspi_f1_backplane,
@@ -704,7 +704,7 @@ static int bcmf_gspi_init_alp_clock(FAR bcmf_gspi_dev_t *gbus)
 
   wlinfo("ALP initialization complete\n");
 
-  nxsig_usleep(100 * 1000);
+  nxsched_usleep(100 * 1000);
 
   return OK;
 }
diff --git a/drivers/wireless/ieee80211/bcm43xxx/bcmf_gspi_f2_frame.c b/drivers/wireless/ieee80211/bcm43xxx/bcmf_gspi_f2_frame.c
index afec9ae4b75..117caacc059 100644
--- a/drivers/wireless/ieee80211/bcm43xxx/bcmf_gspi_f2_frame.c
+++ b/drivers/wireless/ieee80211/bcm43xxx/bcmf_gspi_f2_frame.c
@@ -329,7 +329,7 @@ int bcmf_gspi_send_f2_frame(FAR struct bcmf_dev_s *priv)
       /* TODO handle this case */
 
       wlwarn("No credit to send frame\n");
-      nxsig_usleep(10 * 1000);
+      nxsched_usleep(10 * 1000);
     }
 
   if (nxmutex_lock(&gbus->queue_lock) < 0)
diff --git a/drivers/wireless/ieee80211/bcm43xxx/bcmf_interface.c b/drivers/wireless/ieee80211/bcm43xxx/bcmf_interface.c
index 5ce09213688..c36e05cc052 100644
--- a/drivers/wireless/ieee80211/bcm43xxx/bcmf_interface.c
+++ b/drivers/wireless/ieee80211/bcm43xxx/bcmf_interface.c
@@ -123,7 +123,7 @@ bcmf_interface_frame_t
 
       nxmutex_unlock(&ibus->queue_lock);
 
-      nxsig_usleep(10 * 1000);
+      nxsched_usleep(10 * 1000);
 
       if (!block)
         {
diff --git a/drivers/wireless/ieee80211/bcm43xxx/bcmf_sdio.c b/drivers/wireless/ieee80211/bcm43xxx/bcmf_sdio.c
index dd9a052f40a..eec2959d3fd 100644
--- a/drivers/wireless/ieee80211/bcm43xxx/bcmf_sdio.c
+++ b/drivers/wireless/ieee80211/bcm43xxx/bcmf_sdio.c
@@ -171,7 +171,7 @@ int bcmf_sdio_kso_enable(FAR struct bcmf_sdio_dev_s *sbus, bool enable)
               return ret;
             }
 
-          nxsig_usleep(100 * 1000);
+          nxsched_usleep(100 * 1000);
           ret = bcmf_read_reg(sbus, 1, SBSDIO_FUNC1_SLEEPCSR, &value);
           if (ret != OK)
             {
@@ -241,7 +241,7 @@ int bcmf_sdio_bus_sleep(FAR struct bcmf_sdio_dev_s *sbus, bool sleep)
 
           /* Wait for High Throughput clock */
 
-          nxsig_usleep(100 * 1000);
+          nxsched_usleep(100 * 1000);
           ret = bcmf_read_reg(sbus, 1, SBSDIO_FUNC1_CHIPCLKCSR, &value);
 
           if (ret != OK)
@@ -354,7 +354,7 @@ int bcmf_probe(FAR struct bcmf_sdio_dev_s *sbus)
 #endif
 
   SDIO_CLOCK(sbus->sdio_dev, CLOCK_SD_TRANSFER_4BIT);
-  nxsig_usleep(BCMF_CLOCK_SETUP_DELAY_MS * 1000);
+  nxsched_usleep(BCMF_CLOCK_SETUP_DELAY_MS * 1000);
 
   /* Enable bus FN1 */
 
@@ -396,7 +396,7 @@ int bcmf_businitialize(FAR struct bcmf_sdio_dev_s *sbus)
   loops = 10;
   while (--loops > 0)
     {
-      nxsig_usleep(10 * 1000);
+      nxsched_usleep(10 * 1000);
       ret = bcmf_read_reg(sbus, 1, SBSDIO_FUNC1_CHIPCLKCSR, &value);
 
       if (ret != OK)
@@ -540,12 +540,12 @@ int bcmf_hwinitialize(FAR struct bcmf_sdio_dev_s *sbus)
   /* Reset device */
 
   bcmf_board_reset(sbus->minor, true);
-  nxsig_usleep(BCMF_DEVICE_RESET_DELAY_MS * 1000);
+  nxsched_usleep(BCMF_DEVICE_RESET_DELAY_MS * 1000);
   bcmf_board_reset(sbus->minor, false);
 
   /* Wait for device to start */
 
-  nxsig_usleep(BCMF_DEVICE_START_DELAY_MS * 1000);
+  nxsched_usleep(BCMF_DEVICE_START_DELAY_MS * 1000);
 
   return OK;
 }
@@ -880,7 +880,7 @@ int bcmf_bus_sdio_active(FAR struct bcmf_dev_s *priv, bool active)
       goto exit_uninit_hw;
     }
 
-  nxsig_usleep(100 * 1000);
+  nxsched_usleep(100 * 1000);
 
   ret = bcmf_bus_setup_interrupts(sbus);
   if (ret != OK)
@@ -968,7 +968,7 @@ int bcmf_sdio_thread(int argc, char **argv)
 
   /*  FIXME wait for the chip to be ready to receive commands */
 
-  nxsig_usleep(50 * 1000);
+  nxsched_usleep(50 * 1000);
 
   while (true)
     {
diff --git a/drivers/wireless/lpwan/sx127x/sx127x.c b/drivers/wireless/lpwan/sx127x/sx127x.c
index 655d21c983c..635af9f8dbf 100644
--- a/drivers/wireless/lpwan/sx127x/sx127x.c
+++ b/drivers/wireless/lpwan/sx127x/sx127x.c
@@ -2882,7 +2882,7 @@ static int sx127x_lora_opmode_set(FAR struct sx127x_dev_s *dev,
 
   /* Wait for mode ready. REVISIT: do we need this ? */
 
-  nxsig_usleep(250);
+  nxsched_usleep(250);
 
 errout:
   sx127x_unlock(dev->spi);
@@ -3685,7 +3685,7 @@ static bool sx127x_channel_scan(FAR struct sx127x_dev_s *dev,
 
       /* Wait some time */
 
-      nxsig_usleep(1000);
+      nxsched_usleep(1000);
     }
   while (tstart.tv_sec + chanscan->stime > tnow.tv_sec);
 
@@ -4046,7 +4046,7 @@ static int sx127x_calibration(FAR struct sx127x_dev_s *dev, uint32_t freq)
     {
       /* Wait 10ms */
 
-      nxsig_usleep(10000);
+      nxsched_usleep(10000);
 
       /* Get register */
 
diff --git a/drivers/wireless/nrf24l01.c b/drivers/wireless/nrf24l01.c
index 716386f7e97..2e0e00e4eb4 100644
--- a/drivers/wireless/nrf24l01.c
+++ b/drivers/wireless/nrf24l01.c
@@ -772,7 +772,7 @@ static void nrf24l01_tostate(FAR struct nrf24l01_dev_s *dev,
       /* Leaving power down (note: new state cannot be power down here) */
 
       nrf24l01_setregbit(dev, NRF24L01_CONFIG, NRF24L01_PWR_UP, true);
-      nxsig_usleep(NRF24L01_TPD2STBY_DELAY);
+      nxsched_usleep(NRF24L01_TPD2STBY_DELAY);
     }
 
   /* Entering new state */
diff --git a/drivers/wireless/spirit/lib/spirit_radio.c b/drivers/wireless/spirit/lib/spirit_radio.c
index 7616ffff6b5..9cbc0f3e6c3 100644
--- a/drivers/wireless/spirit/lib/spirit_radio.c
+++ b/drivers/wireless/spirit/lib/spirit_radio.c
@@ -225,7 +225,7 @@ int spirit_radio_initialize(FAR struct spirit_library_s *spirit,
 
   /* Delay for state transition */
 
-  nxsig_usleep(100);
+  nxsched_usleep(100);
 
   /* Wait for the device to enter STANDBY */
 
@@ -263,7 +263,7 @@ int spirit_radio_initialize(FAR struct spirit_library_s *spirit,
 
   /* Delay for state transition */
 
-  nxsig_usleep(100);
+  nxsched_usleep(100);
 
   /* Make sure that the device becomes READY */
 
diff --git a/fs/rpmsgfs/rpmsgfs.c b/fs/rpmsgfs/rpmsgfs.c
index e3674dcb07f..733e67e3516 100644
--- a/fs/rpmsgfs/rpmsgfs.c
+++ b/fs/rpmsgfs/rpmsgfs.c
@@ -267,7 +267,7 @@ static void rpmsgfs_mkpath(FAR struct rpmsgfs_mountpt_s *fs,
           break;
         }
 
-      nxsig_usleep(RPMSGFS_RETRY_DELAY_MS * USEC_PER_MSEC);
+      nxsched_usleep(RPMSGFS_RETRY_DELAY_MS * USEC_PER_MSEC);
       fs->timeout -= RPMSGFS_RETRY_DELAY_MS;
     }
 }
diff --git a/graphics/nxmu/nxmu_start.c b/graphics/nxmu/nxmu_start.c
index 4509d5a1179..bcc9257b18e 100644
--- a/graphics/nxmu/nxmu_start.c
+++ b/graphics/nxmu/nxmu_start.c
@@ -234,7 +234,7 @@ int nxmu_start(int display, int plane)
        * this operation cannot be done from the IDLE thread!
        */
 
-      nxsig_usleep(50 * 1000);
+      nxsched_usleep(50 * 1000);
     }
 
   return OK;
diff --git a/sched/group/group_killchildren.c b/sched/group/group_killchildren.c
index d0085a6f741..bb2f01424f8 100644
--- a/sched/group/group_killchildren.c
+++ b/sched/group/group_killchildren.c
@@ -191,7 +191,7 @@ int group_kill_children(FAR struct tcb_s *tcb)
               break;
             }
 
-          nxsig_usleep(USEC_PER_MSEC);
+          nxsched_usleep(USEC_PER_MSEC);
 
 #  if CONFIG_GROUP_KILL_CHILDREN_TIMEOUT_MS > 0
           if (--ret < 0)
diff --git a/sched/paging/pg_worker.c b/sched/paging/pg_worker.c
index c7816369a3d..74d60b63003 100644
--- a/sched/paging/pg_worker.c
+++ b/sched/paging/pg_worker.c
@@ -545,7 +545,7 @@ int pg_worker(int argc, FAR char *argv[])
     {
       /* Wait awhile.  We will wait here until either the configurable
        * timeout elapses or until we are awakened by a signal (which
-       * terminates the nxsig_usleep with an EINTR error).  Note that
+       * terminates the nxsched_usleep with an EINTR error).  Note that
        * interrupts will be re- enabled while this task sleeps.
        *
        * The timeout is a failsafe that will handle any cases where a single
@@ -553,7 +553,7 @@ int pg_worker(int argc, FAR char *argv[])
        * supports timeouts for case of non-blocking, asynchronous fills.
        */
 
-      nxsig_usleep(CONFIG_PAGING_WORKPERIOD);
+      nxsched_usleep(CONFIG_PAGING_WORKPERIOD);
 
       /* The page fill worker thread will be awakened on one of 3 conditions:
        *
diff --git a/wireless/bluetooth/bt_hcicore.c b/wireless/bluetooth/bt_hcicore.c
index 98b02e61d30..91df9b8543f 100644
--- a/wireless/bluetooth/bt_hcicore.c
+++ b/wireless/bluetooth/bt_hcicore.c
@@ -1539,7 +1539,7 @@ static void cmd_queue_deinit(void)
 
   while (g_btdev.tx_status == ENOTCONN)
     {
-      nxsig_usleep(1000);
+      nxsched_usleep(1000);
     }
 
   /* Deinitialization */