net/utils/net_bufpool: add lock to struct net_bufpool_s and bufpool_navail

Add a lock to net_bufpool to simplify the protocol stack code.

Signed-off-by: zhanghongyu <zhanghongyu@xiaomi.com>

arch/arm/src/stm32h5/Kconfig

@@ -4525,6 +4525,19 @@ config LPUART1_RXDMA
 	---help---
 		In high data rate usage, Rx DMA may eliminate Rx overrun errors
 
+config LPUART1_UNCONFIG_RX_ON_CLOSE
+	bool "Unconfigure LPUART1 RX pin on close"
+	default n
+
+config LPUART1_UNCONFIG_TX_ON_CLOSE
+	bool "Unconfigure LPUART1 TX pin on close"
+	default n
+
+config LPUART1_UNCONFIG_DIR_ON_CLOSE
+	depends on LPUART1_RS485
+	bool "Unconfigure LPUART1 DIR pin on close"
+	default n
+
 endif # LPUART1_SERIALDRIVER
 
 choice
@@ -4566,6 +4579,19 @@ config USART1_RXDMA
 	---help---
 		In high data rate usage, Rx DMA may eliminate Rx overrun errors
 
+config USART1_UNCONFIG_RX_ON_CLOSE
+	bool "Unconfigure USART1 RX pin on close"
+	default n
+
+config USART1_UNCONFIG_TX_ON_CLOSE
+	bool "Unconfigure USART1 TX pin on close"
+	default n
+
+config USART1_UNCONFIG_DIR_ON_CLOSE
+	depends on USART1_RS485
+	bool "Unconfigure USART1 DIR pin on close"
+	default n
+
 endif # USART1_SERIALDRIVER
 
 choice
@@ -4607,6 +4633,19 @@ config USART2_RXDMA
 	---help---
 		In high data rate usage, Rx DMA may eliminate Rx overrun errors
 
+config USART2_UNCONFIG_RX_ON_CLOSE
+	bool "Unconfigure USART2 RX pin on close"
+	default n
+
+config USART2_UNCONFIG_TX_ON_CLOSE
+	bool "Unconfigure USART2 TX pin on close"
+	default n
+
+config USART2_UNCONFIG_DIR_ON_CLOSE
+	depends on USART2_RS485
+	bool "Unconfigure USART2 DIR pin on close"
+	default n
+
 endif # USART2_SERIALDRIVER
 
 choice
@@ -4648,6 +4687,19 @@ config USART3_RXDMA
 	---help---
 		In high data rate usage, Rx DMA may eliminate Rx overrun errors
 
+config USART3_UNCONFIG_RX_ON_CLOSE
+	bool "Unconfigure USART3 RX pin on close"
+	default n
+
+config USART3_UNCONFIG_TX_ON_CLOSE
+	bool "Unconfigure USART3 TX pin on close"
+	default n
+
+config USART3_UNCONFIG_DIR_ON_CLOSE
+	depends on USART3_RS485
+	bool "Unconfigure USART3 DIR pin on close"
+	default n
+
 endif # USART3_SERIALDRIVER
 
 choice
@@ -4689,6 +4741,19 @@ config UART4_RXDMA
 	---help---
 		In high data rate usage, Rx DMA may eliminate Rx overrun errors
 
+config UART4_UNCONFIG_RX_ON_CLOSE
+	bool "Unconfigure UART4 RX pin on close"
+	default n
+
+config UART4_UNCONFIG_TX_ON_CLOSE
+	bool "Unconfigure UART4 TX pin on close"
+	default n
+
+config UART4_UNCONFIG_DIR_ON_CLOSE
+	depends on UART4_RS485
+	bool "Unconfigure UART4 DIR pin on close"
+	default n
+
 endif # UART4_SERIALDRIVER
 
 choice
@@ -4730,6 +4795,19 @@ config UART5_RXDMA
 	---help---
 		In high data rate usage, Rx DMA may eliminate Rx overrun errors
 
+config UART5_UNCONFIG_RX_ON_CLOSE
+	bool "Unconfigure UART5 RX pin on close"
+	default n
+
+config UART5_UNCONFIG_TX_ON_CLOSE
+	bool "Unconfigure UART5 TX pin on close"
+	default n
+
+config UART5_UNCONFIG_DIR_ON_CLOSE
+	depends on UART5_RS485
+	bool "Unconfigure UART5 DIR pin on close"
+	default n
+
 endif # UART5_SERIALDRIVER
 
 choice
@@ -4771,6 +4849,19 @@ config USART6_RXDMA
 	---help---
 		In high data rate usage, Rx DMA may eliminate Rx overrun errors
 
+config USART6_UNCONFIG_RX_ON_CLOSE
+	bool "Unconfigure USART6 RX pin on close"
+	default n
+
+config USART6_UNCONFIG_TX_ON_CLOSE
+	bool "Unconfigure USART6 TX pin on close"
+	default n
+
+config USART6_UNCONFIG_DIR_ON_CLOSE
+	depends on USART6_RS485
+	bool "Unconfigure USART6 DIR pin on close"
+	default n
+
 endif # USART6_SERIALDRIVER
 
 if UART7_SERIALDRIVER
@@ -4800,6 +4891,19 @@ config UART7_RXDMA
 	---help---
 		In high data rate usage, Rx DMA may eliminate Rx overrun errors
 
+config UART7_UNCONFIG_RX_ON_CLOSE
+	bool "Unconfigure UART7 RX pin on close"
+	default n
+
+config UART7_UNCONFIG_TX_ON_CLOSE
+	bool "Unconfigure UART7 TX pin on close"
+	default n
+
+config UART7_UNCONFIG_DIR_ON_CLOSE
+	depends on UART7_RS485
+	bool "Unconfigure UART7 DIR pin on close"
+	default n
+
 endif # UART7_SERIALDRIVER
 
 if UART8_SERIALDRIVER
@@ -4829,6 +4933,19 @@ config UART8_RXDMA
 	---help---
 		In high data rate usage, Rx DMA may eliminate Rx overrun errors
 
+config UART8_UNCONFIG_RX_ON_CLOSE
+	bool "Unconfigure UART8 RX pin on close"
+	default n
+
+config UART8_UNCONFIG_TX_ON_CLOSE
+	bool "Unconfigure UART8 TX pin on close"
+	default n
+
+config UART8_UNCONFIG_DIR_ON_CLOSE
+	depends on UART8_RS485
+	bool "Unconfigure UART8 DIR pin on close"
+	default n
+
 endif # UART8_SERIALDRIVER
 
 if UART9_SERIALDRIVER
@@ -4858,6 +4975,19 @@ config UART9_RXDMA
 	---help---
 		In high data rate usage, Rx DMA may eliminate Rx overrun errors
 
+config UART9_UNCONFIG_RX_ON_CLOSE
+	bool "Unconfigure UART9 RX pin on close"
+	default n
+
+config UART9_UNCONFIG_TX_ON_CLOSE
+	bool "Unconfigure UART9 TX pin on close"
+	default n
+
+config UART9_UNCONFIG_DIR_ON_CLOSE
+	depends on UART9_RS485
+	bool "Unconfigure UART9 DIR pin on close"
+	default n
+
 endif # UART9_SERIALDRIVER
 
 if USART10_SERIALDRIVER
@@ -4887,6 +5017,19 @@ config USART10_RXDMA
 	---help---
 		In high data rate usage, Rx DMA may eliminate Rx overrun errors
 
+config USART10_UNCONFIG_RX_ON_CLOSE
+	bool "Unconfigure USART10 RX pin on close"
+	default n
+
+config USART10_UNCONFIG_TX_ON_CLOSE
+	bool "Unconfigure USART10 TX pin on close"
+	default n
+
+config USART10_UNCONFIG_DIR_ON_CLOSE
+	depends on USART10_RS485
+	bool "Unconfigure USART10 DIR pin on close"
+	default n
+
 endif # USART10_SERIALDRIVER
 
 if USART11_SERIALDRIVER
@@ -4916,6 +5059,19 @@ config USART11_RXDMA
 	---help---
 		In high data rate usage, Rx DMA may eliminate Rx overrun errors
 
+config USART11_UNCONFIG_RX_ON_CLOSE
+	bool "Unconfigure USART11 RX pin on close"
+	default n
+
+config USART11_UNCONFIG_TX_ON_CLOSE
+	bool "Unconfigure USART11 TX pin on close"
+	default n
+
+config USART11_UNCONFIG_DIR_ON_CLOSE
+	depends on USART11_RS485
+	bool "Unconfigure USART11 DIR pin on close"
+	default n
+
 endif # USART11_SERIALDRIVER
 
 if UART12_SERIALDRIVER
@@ -4945,6 +5101,19 @@ config UART12_RXDMA
 	---help---
 		In high data rate usage, Rx DMA may eliminate Rx overrun errors
 
+config UART12_UNCONFIG_RX_ON_CLOSE
+	bool "Unconfigure UART12 RX pin on close"
+	default n
+
+config UART12_UNCONFIG_TX_ON_CLOSE
+	bool "Unconfigure UART12 TX pin on close"
+	default n
+
+config UART12_UNCONFIG_DIR_ON_CLOSE
+	depends on UART12_RS485
+	bool "Unconfigure UART12 DIR pin on close"
+	default n
+
 endif # UART12_SERIALDRIVER
 
 if STM32H5_SERIALDRIVER

arch/arm/src/stm32h5/stm32_serial.c

@@ -125,6 +125,12 @@
 #  define CONFIG_STM32H5_PM_SERIAL_ACTIVITY  10
 #endif
 
+/* USART Unconfigure bits */
+
+#define USART_UNCONFIGURE_RX                    (1 << 0)
+#define USART_UNCONFIGURE_TX                    (1 << 1)
+#define USART_UNCONFIGURE_DIR                   (1 << 2)
+
 /* Keep track if a Break was set
  *
  * Note:
@@ -214,10 +220,13 @@ struct stm32_serial_s
 #endif
 
 #ifdef HAVE_RS485
-  const uint32_t    rs485_dir_gpio;     /* U[S]ART RS-485 DIR GPIO pin configuration */
-  const bool        rs485_dir_polarity; /* U[S]ART RS-485 DIR pin state for TX enabled */
+  const uint32_t    rs485_dir_gpio; /* U[S]ART RS-485 DIR GPIO pin configuration */
+  uint8_t           rs485_flags;    /* U[S]ART RS-485 flags
+                                     * (compatible with struct serial_rs485)
+                                     */
 #endif
-  const bool        islpuart;  /* Is this device a Low Power UART? */
+  const uint8_t     unconfigure; /* Unconfigure pins on close */
+  const bool        islpuart;    /* Is this device a Low Power UART? */
   spinlock_t        lock;
 };
 
@@ -472,12 +481,26 @@ static struct stm32_serial_s g_lpuart1priv =
 #  ifdef CONFIG_USART1_RS485
   .rs485_dir_gpio = GPIO_LPUART1_RS485_DIR,
 #    if (CONFIG_USART1_RS485_DIR_POLARITY == 0)
-  .rs485_dir_polarity = false,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
 #    else
-  .rs485_dir_polarity = true,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND,
 #    endif
 #  endif
   .lock               = SP_UNLOCKED,
+  .unconfigure        = 0
+#if defined(CONFIG_LPUART1_UNCONFIG_RX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_RX
+#endif
+#if defined(CONFIG_LPUART1_UNCONFIG_TX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_TX
+#endif
+#if defined(CONFIG_LPUART1_UNCONFIG_DIR_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_DIR
+#endif
+      ,
 };
 #endif
 
@@ -533,12 +556,26 @@ static struct stm32_serial_s g_usart1priv =
 #  ifdef CONFIG_USART1_RS485
   .rs485_dir_gpio = GPIO_USART1_RS485_DIR,
 #    if (CONFIG_USART1_RS485_DIR_POLARITY == 0)
-  .rs485_dir_polarity = false,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
 #    else
-  .rs485_dir_polarity = true,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND,
 #    endif
 #  endif
   .lock               = SP_UNLOCKED,
+  .unconfigure        = 0
+#if defined(CONFIG_USART1_UNCONFIG_RX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_RX
+#endif
+#if defined(CONFIG_USART1_UNCONFIG_TX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_TX
+#endif
+#if defined(CONFIG_USART1_UNCONFIG_DIR_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_DIR
+#endif
+      ,
 };
 #endif
 
@@ -596,12 +633,26 @@ static struct stm32_serial_s g_usart2priv =
 #  ifdef CONFIG_USART2_RS485
   .rs485_dir_gpio = GPIO_USART2_RS485_DIR,
 #    if (CONFIG_USART2_RS485_DIR_POLARITY == 0)
-  .rs485_dir_polarity = false,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
 #    else
-  .rs485_dir_polarity = true,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND,
 #    endif
 #  endif
   .lock               = SP_UNLOCKED,
+  .unconfigure        = 0
+#if defined(CONFIG_USART2_UNCONFIG_RX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_RX
+#endif
+#if defined(CONFIG_USART2_UNCONFIG_TX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_TX
+#endif
+#if defined(CONFIG_USART2_UNCONFIG_DIR_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_DIR
+#endif
+      ,
 };
 #endif
 
@@ -659,12 +710,26 @@ static struct stm32_serial_s g_usart3priv =
 #  ifdef CONFIG_USART3_RS485
   .rs485_dir_gpio = GPIO_USART3_RS485_DIR,
 #    if (CONFIG_USART3_RS485_DIR_POLARITY == 0)
-  .rs485_dir_polarity = false,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
 #    else
-  .rs485_dir_polarity = true,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND,
 #    endif
 #  endif
   .lock               = SP_UNLOCKED,
+  .unconfigure        = 0
+#if defined(CONFIG_USART3_UNCONFIG_RX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_RX
+#endif
+#if defined(CONFIG_USART3_UNCONFIG_TX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_TX
+#endif
+#if defined(CONFIG_USART3_UNCONFIG_DIR_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_DIR
+#endif
+      ,
 };
 #endif
 
@@ -722,12 +787,26 @@ static struct stm32_serial_s g_uart4priv =
 #  ifdef CONFIG_UART4_RS485
   .rs485_dir_gpio = GPIO_UART4_RS485_DIR,
 #    if (CONFIG_UART4_RS485_DIR_POLARITY == 0)
-  .rs485_dir_polarity = false,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
 #    else
-  .rs485_dir_polarity = true,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND,
 #    endif
 #  endif
   .lock               = SP_UNLOCKED,
+  .unconfigure        = 0
+#if defined(CONFIG_UART4_UNCONFIG_RX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_RX
+#endif
+#if defined(CONFIG_UART4_UNCONFIG_TX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_TX
+#endif
+#if defined(CONFIG_UART4_UNCONFIG_DIR_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_DIR
+#endif
+      ,
 };
 #endif
 
@@ -785,12 +864,26 @@ static struct stm32_serial_s g_uart5priv =
 #  ifdef CONFIG_UART5_RS485
   .rs485_dir_gpio = GPIO_UART5_RS485_DIR,
 #    if (CONFIG_UART5_RS485_DIR_POLARITY == 0)
-  .rs485_dir_polarity = false,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
 #    else
-  .rs485_dir_polarity = true,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND,
 #    endif
 #  endif
   .lock               = SP_UNLOCKED,
+  .unconfigure        = 0
+#if defined(CONFIG_UART5_UNCONFIG_RX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_RX
+#endif
+#if defined(CONFIG_UART5_UNCONFIG_TX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_TX
+#endif
+#if defined(CONFIG_UART5_UNCONFIG_DIR_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_DIR
+#endif
+      ,
 };
 #endif
 
@@ -848,12 +941,26 @@ static struct stm32_serial_s g_usart6priv =
 #  ifdef CONFIG_USART6_RS485
   .rs485_dir_gpio = GPIO_USART6_RS485_DIR,
 #    if (CONFIG_USART6_RS485_DIR_POLARITY == 0)
-  .rs485_dir_polarity = false,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
 #    else
-  .rs485_dir_polarity = true,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND,
 #    endif
 #  endif
   .lock               = SP_UNLOCKED,
+  .unconfigure        = 0
+#if defined(CONFIG_USART6_UNCONFIG_RX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_RX
+#endif
+#if defined(CONFIG_USART6_UNCONFIG_TX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_TX
+#endif
+#if defined(CONFIG_USART6_UNCONFIG_DIR_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_DIR
+#endif
+      ,
 };
 #endif
 
@@ -911,12 +1018,26 @@ static struct stm32_serial_s g_uart7priv =
 #  ifdef CONFIG_UART7_RS485
   .rs485_dir_gpio = GPIO_UART7_RS485_DIR,
 #    if (CONFIG_UART7_RS485_DIR_POLARITY == 0)
-  .rs485_dir_polarity = false,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
 #    else
-  .rs485_dir_polarity = true,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND,
 #    endif
 #  endif
   .lock               = SP_UNLOCKED,
+  .unconfigure        = 0
+#if defined(CONFIG_UART7_UNCONFIG_RX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_RX
+#endif
+#if defined(CONFIG_UART7_UNCONFIG_TX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_TX
+#endif
+#if defined(CONFIG_UART7_UNCONFIG_DIR_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_DIR
+#endif
+      ,
 };
 #endif
 
@@ -974,12 +1095,26 @@ static struct stm32_serial_s g_uart8priv =
 #  ifdef CONFIG_UART8_RS485
   .rs485_dir_gpio = GPIO_UART8_RS485_DIR,
 #    if (CONFIG_UART8_RS485_DIR_POLARITY == 0)
-  .rs485_dir_polarity = false,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
 #    else
-  .rs485_dir_polarity = true,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND,
 #    endif
 #  endif
   .lock               = SP_UNLOCKED,
+  .unconfigure        = 0
+#if defined(CONFIG_UART8_UNCONFIG_RX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_RX
+#endif
+#if defined(CONFIG_UART8_UNCONFIG_TX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_TX
+#endif
+#if defined(CONFIG_UART8_UNCONFIG_DIR_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_DIR
+#endif
+      ,
 };
 #endif
 
@@ -1037,12 +1172,26 @@ static struct stm32_serial_s g_uart9priv =
 #  ifdef CONFIG_UART9_RS485
   .rs485_dir_gpio = GPIO_UART9_RS485_DIR,
 #    if (CONFIG_UART9_RS485_DIR_POLARITY == 0)
-  .rs485_dir_polarity = false,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
 #    else
-  .rs485_dir_polarity = true,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND,
 #    endif
 #  endif
   .lock               = SP_UNLOCKED,
+  .unconfigure        = 0
+#if defined(CONFIG_UART9_UNCONFIG_RX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_RX
+#endif
+#if defined(CONFIG_UART9_UNCONFIG_TX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_TX
+#endif
+#if defined(CONFIG_UART9_UNCONFIG_DIR_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_DIR
+#endif
+      ,
 };
 #endif
 
@@ -1100,12 +1249,26 @@ static struct stm32_serial_s g_usart10priv =
 #  ifdef CONFIG_USART10_RS485
   .rs485_dir_gpio = GPIO_USART10_RS485_DIR,
 #    if (CONFIG_USART10_RS485_DIR_POLARITY == 0)
-  .rs485_dir_polarity = false,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
 #    else
-  .rs485_dir_polarity = true,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND,
 #    endif
 #  endif
   .lock               = SP_UNLOCKED,
+  .unconfigure        = 0
+#if defined(CONFIG_USART10_UNCONFIG_RX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_RX
+#endif
+#if defined(CONFIG_USART10_UNCONFIG_TX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_TX
+#endif
+#if defined(CONFIG_USART10_UNCONFIG_DIR_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_DIR
+#endif
+      ,
 };
 #endif
 
@@ -1163,12 +1326,26 @@ static struct stm32_serial_s g_usart11priv =
 #  ifdef CONFIG_USART11_RS485
   .rs485_dir_gpio = GPIO_USART11_RS485_DIR,
 #    if (CONFIG_USART11_RS485_DIR_POLARITY == 0)
-  .rs485_dir_polarity = false,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
 #    else
-  .rs485_dir_polarity = true,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND,
 #    endif
 #  endif
   .lock               = SP_UNLOCKED,
+  .unconfigure        = 0
+#if defined(CONFIG_USART11_UNCONFIG_RX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_RX
+#endif
+#if defined(CONFIG_USART11_UNCONFIG_TX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_TX
+#endif
+#if defined(CONFIG_USART11_UNCONFIG_DIR_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_DIR
+#endif
+      ,
 };
 #endif
 
@@ -1226,12 +1403,26 @@ static struct stm32_serial_s g_uart12priv =
 #  ifdef CONFIG_UART12_RS485
   .rs485_dir_gpio = GPIO_UART12_RS485_DIR,
 #    if (CONFIG_UART12_RS485_DIR_POLARITY == 0)
-  .rs485_dir_polarity = false,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
 #    else
-  .rs485_dir_polarity = true,
+  .rs485_flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND,
 #    endif
 #  endif
   .lock               = SP_UNLOCKED,
+  .unconfigure        = 0
+#if defined(CONFIG_UART12_UNCONFIG_RX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_RX
+#endif
+#if defined(CONFIG_UART12_UNCONFIG_TX_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_TX
+#endif
+#if defined(CONFIG_UART12_UNCONFIG_DIR_ON_CLOSE)
+                      |
+                      USART_UNCONFIGURE_DIR
+#endif
+      ,
 };
 #endif
 
@@ -2005,10 +2196,11 @@ static int stm32serial_setup(struct uart_dev_s *dev)
 #endif
 
 #ifdef HAVE_RS485
-  if (priv->rs485_dir_gpio != 0)
+  if ((priv->rs485_flags & SER_RS485_ENABLED) != 0)
     {
       stm32_configgpio(priv->rs485_dir_gpio);
-      stm32_gpiowrite(priv->rs485_dir_gpio, !priv->rs485_dir_polarity);
+      stm32_gpiowrite(priv->rs485_dir_gpio,
+                     (bool) (priv->rs485_flags & SER_RS485_RTS_AFTER_SEND));
     }
 #endif
 
@@ -2242,8 +2434,15 @@ static void stm32serial_shutdown(struct uart_dev_s *dev)
    * then this may need to be a configuration option.
    */
 
-  stm32_unconfiggpio(priv->tx_gpio);
-  stm32_unconfiggpio(priv->rx_gpio);
+  if (priv->unconfigure & USART_UNCONFIGURE_TX)
+    {
+      stm32_unconfiggpio(priv->tx_gpio);
+    }
+
+  if (priv->unconfigure & USART_UNCONFIGURE_RX)
+    {
+      stm32_unconfiggpio(priv->rx_gpio);
+    }
 
 #ifdef CONFIG_SERIAL_OFLOWCONTROL
   if (priv->cts_gpio != 0)
@@ -2260,7 +2459,8 @@ static void stm32serial_shutdown(struct uart_dev_s *dev)
 #endif
 
 #ifdef HAVE_RS485
-  if (priv->rs485_dir_gpio != 0)
+  if ((priv->rs485_dir_gpio != 0) &&
+      (priv->unconfigure & USART_UNCONFIGURE_DIR))
     {
       stm32_unconfiggpio(priv->rs485_dir_gpio);
     }
@@ -2429,7 +2629,9 @@ static int stm32serial_interrupt(int irq, void *context, void *arg)
           (priv->ie & USART_CR1_TCIE) != 0 &&
           (priv->ie & USART_CR1_TXEIE) == 0)
         {
-          stm32_gpiowrite(priv->rs485_dir_gpio, !priv->rs485_dir_polarity);
+          stm32_gpiowrite(priv->rs485_dir_gpio,
+                         (bool) (priv->rs485_flags &
+                          SER_RS485_RTS_AFTER_SEND));
           stm32serial_restoreusartint(priv, priv->ie & ~USART_CR1_TCIE);
         }
 #endif
@@ -2479,6 +2681,110 @@ static int stm32serial_interrupt(int irq, void *context, void *arg)
   return OK;
 }
 
+/****************************************************************************
+ * Name: stm32serial_set_rs485_mode
+ *
+ * Description:
+ *   Handle mode set ioctl (TIOCSRS485) to enable
+ *   and disable RS-485 mode.  This is part of the serial ioctl logic.
+ *
+ *
+ ****************************************************************************/
+
+#ifdef HAVE_RS485
+static inline int stm32serial_set_rs485_mode(struct stm32_serial_s *priv,
+                                    const struct serial_rs485 *mode)
+{
+  irqstate_t flags;
+
+  DEBUGASSERT(priv && mode);
+  if (priv->rs485_dir_gpio == 0)
+    {
+      /* Can't configure RS485 dir pin if pin is not defined */
+
+      return -ENOTTY;
+    }
+
+  flags = enter_critical_section();
+  priv->sr = stm32serial_getreg(priv, STM32_USART_ISR_OFFSET);
+
+  priv->rs485_flags = mode->flags &
+                     (SER_RS485_ENABLED |
+                      SER_RS485_RTS_ON_SEND |
+                      SER_RS485_RTS_AFTER_SEND |
+                      SER_RS485_RX_DURING_TX);
+/* Cases:
+ * Enabling, serial transfer currently in progress:
+ *  Set the pin to the transfer in progress state and let the interrupt take
+ *  care of it
+ * Enabling, no serial transfer currently in progress:
+ *  Set the pin to the no transfer in progress state.
+ */
+
+  if (mode->flags & SER_RS485_ENABLED)
+    {
+      stm32_configgpio(priv->rs485_dir_gpio);
+      if ((priv->sr & USART_ISR_TC) != 0)
+        {
+          /* Transmission is complete, set to "after send' state */
+
+          stm32_gpiowrite(priv->rs485_dir_gpio, (bool) (priv->rs485_flags &
+                          SER_RS485_RTS_AFTER_SEND));
+        }
+      else
+        {
+          /* Transmission is currently in progress, set to "on send" state */
+
+          stm32_gpiowrite(priv->rs485_dir_gpio, (bool) (priv->rs485_flags &
+                          SER_RS485_RTS_ON_SEND));
+        }
+    }
+  else
+    {
+      if (priv->unconfigure & USART_UNCONFIGURE_DIR)
+        {
+          stm32_unconfiggpio(priv->rs485_dir_gpio);
+        }
+    }
+
+  leave_critical_section(flags);
+  return OK;
+}
+#endif
+
+/****************************************************************************
+ * Name: stm32serial_get_rs485_mode
+ *
+ * Description:
+ *   Handle RS485 mode get ioctl (TIOCGRS485) to get the
+ *   current RS-485 mode.
+ *
+ ****************************************************************************/
+
+#ifdef HAVE_RS485
+static inline int stm32serial_get_rs485_mode(struct stm32_serial_s *priv,
+                                    struct serial_rs485 *mode)
+{
+  irqstate_t flags;
+
+  DEBUGASSERT(priv && mode);
+  flags = enter_critical_section();
+
+  /* Assume disabled */
+
+  memset(mode, 0, sizeof(struct serial_rs485));
+
+  mode->flags = priv->rs485_flags &
+              (SER_RS485_ENABLED |
+               SER_RS485_RTS_ON_SEND |
+               SER_RS485_RTS_AFTER_SEND |
+               SER_RS485_RX_DURING_TX);
+
+  leave_critical_section(flags);
+  return OK;
+}
+#endif
+
 /****************************************************************************
  * Name: stm32serial_ioctl
  *
@@ -2852,7 +3158,21 @@ static int stm32serial_ioctl(struct file *filep, int cmd,
       break;
 #  endif
 #endif
+#ifdef HAVE_RS485
+    case TIOCSRS485:  /* Set RS485 mode, arg: pointer to struct serial_rs485 */
+      {
+        ret = stm32serial_set_rs485_mode(
+          priv, (const struct serial_rs485 *)((uintptr_t)arg));
+      }
+      break;
 
+    case TIOCGRS485:  /* Get RS485 mode, arg: pointer to struct serial_rs485 */
+      {
+        ret = stm32serial_get_rs485_mode(
+          priv, (struct serial_rs485 *)((uintptr_t)arg));
+      }
+      break;
+#endif
     default:
       ret = -ENOTTY;
       break;
@@ -3308,9 +3628,10 @@ static void stm32serial_send(struct uart_dev_s *dev, int ch)
     (struct stm32_serial_s *)dev->priv;
 
 #ifdef HAVE_RS485
-  if (priv->rs485_dir_gpio != 0)
+  if ((priv->rs485_flags & SER_RS485_ENABLED) != 0)
     {
-      stm32_gpiowrite(priv->rs485_dir_gpio, priv->rs485_dir_polarity);
+      stm32_gpiowrite(priv->rs485_dir_gpio, (bool) (priv->rs485_flags &
+                      SER_RS485_RTS_ON_SEND));
     }
 #endif
 
@@ -3353,7 +3674,7 @@ static void stm32serial_txint(struct uart_dev_s *dev, bool enable)
        */
 
 #  ifdef HAVE_RS485
-      if (priv->rs485_dir_gpio != 0)
+      if ((priv->rs485_flags & SER_RS485_ENABLED) != 0)
         {
           ie |= USART_CR1_TCIE;
         }

fs/vfs/fs_select.c

@@ -204,7 +204,7 @@ int select(int nfds, FAR fd_set *readfds, FAR fd_set *writefds,
     {
       /* Calculate the timeout in milliseconds */
 
-      msec = timeout->tv_sec * 1000 + timeout->tv_usec / 1000;
+      msec = timeout->tv_sec * 1000 + (timeout->tv_usec + 999) / 1000;
     }
   else
     {

include/sys/socket.h

@@ -230,10 +230,12 @@
 
 /* Protocol-level socket operations. */
 
-#define SOL_IP          IPPROTO_IP   /* See options in include/netinet/ip.h */
-#define SOL_IPV6        IPPROTO_IPV6 /* See options in include/netinet/ip6.h */
-#define SOL_TCP         IPPROTO_TCP  /* See options in include/netinet/tcp.h */
-#define SOL_UDP         IPPROTO_UDP  /* See options in include/netinit/udp.h */
+#define SOL_IP          IPPROTO_IP     /* See options in include/netinet/in.h */
+#define SOL_IPV6        IPPROTO_IPV6   /* See options in include/netinet/in.h */
+#define SOL_TCP         IPPROTO_TCP    /* See options in include/netinet/in.h */
+#define SOL_UDP         IPPROTO_UDP    /* See options in include/netinet/in.h */
+#define SOL_RAW         IPPROTO_RAW    /* See options in include/netinet/in.h */
+#define SOL_ICMPV6      IPPROTO_ICMPV6 /* See options in include/netinet/in.h */
 
 /* Bluetooth-level operations. */
 

net/can/can_conn.c

@@ -62,7 +62,6 @@
 NET_BUFPOOL_DECLARE(g_can_connections, sizeof(struct can_conn_s),
                     CONFIG_CAN_PREALLOC_CONNS, CONFIG_CAN_ALLOC_CONNS,
                     CONFIG_CAN_MAX_CONNS);
-static mutex_t g_free_lock = NXMUTEX_INITIALIZER;
 
 /* A list of all allocated NetLink connections */
 
@@ -100,7 +99,7 @@ FAR struct can_conn_s *can_alloc(void)
 
   /* The free list is protected by a a mutex. */
 
-  nxmutex_lock(&g_free_lock);
+  NET_BUFPOLL_LOCK(g_can_connections);
 
   conn = NET_BUFPOOL_TRYALLOC(g_can_connections);
   if (conn != NULL)
@@ -128,7 +127,7 @@ FAR struct can_conn_s *can_alloc(void)
       dq_addlast(&conn->sconn.node, &g_active_can_connections);
     }
 
-  nxmutex_unlock(&g_free_lock);
+  NET_BUFPOLL_UNLOCK(g_can_connections);
   return conn;
 }
 
@@ -147,7 +146,7 @@ void can_free(FAR struct can_conn_s *conn)
 
   DEBUGASSERT(conn->crefs == 0);
 
-  nxmutex_lock(&g_free_lock);
+  NET_BUFPOLL_LOCK(g_can_connections);
 
   /* Remove the connection from the active list */
 
@@ -157,7 +156,7 @@ void can_free(FAR struct can_conn_s *conn)
 
   NET_BUFPOOL_FREE(g_can_connections, conn);
 
-  nxmutex_unlock(&g_free_lock);
+  NET_BUFPOLL_UNLOCK(g_can_connections);
 }
 
 /****************************************************************************

net/icmp/icmp_conn.c

@@ -62,7 +62,6 @@
 NET_BUFPOOL_DECLARE(g_icmp_connections, sizeof(struct icmp_conn_s),
                     CONFIG_NET_ICMP_PREALLOC_CONNS,
                     CONFIG_NET_ICMP_ALLOC_CONNS, CONFIG_NET_ICMP_MAX_CONNS);
-static mutex_t g_free_lock = NXMUTEX_INITIALIZER;
 
 /* A list of all allocated IPPROTO_ICMP socket connections */
 
@@ -85,24 +84,21 @@ static dq_queue_t g_active_icmp_connections;
 FAR struct icmp_conn_s *icmp_alloc(void)
 {
   FAR struct icmp_conn_s *conn = NULL;
-  int ret;
 
   /* The free list is protected by a mutex. */
 
-  ret = nxmutex_lock(&g_free_lock);
-  if (ret >= 0)
+  NET_BUFPOLL_LOCK(g_icmp_connections);
+
+  conn = NET_BUFPOOL_TRYALLOC(g_icmp_connections);
+  if (conn != NULL)
     {
-      conn = NET_BUFPOOL_TRYALLOC(g_icmp_connections);
-      if (conn != NULL)
-        {
-          /* Enqueue the connection into the active list */
+      /* Enqueue the connection into the active list */
 
-          dq_addlast(&conn->sconn.node, &g_active_icmp_connections);
-        }
-
-      nxmutex_unlock(&g_free_lock);
+      dq_addlast(&conn->sconn.node, &g_active_icmp_connections);
     }
 
+  NET_BUFPOLL_UNLOCK(g_icmp_connections);
+
   return conn;
 }
 
@@ -123,7 +119,7 @@ void icmp_free(FAR struct icmp_conn_s *conn)
 
   /* Take the mutex (perhaps waiting) */
 
-  nxmutex_lock(&g_free_lock);
+  NET_BUFPOLL_LOCK(g_icmp_connections);
 
   /* Is this the last reference on the connection?  It might not be if the
    * socket was cloned.
@@ -146,7 +142,7 @@ void icmp_free(FAR struct icmp_conn_s *conn)
       NET_BUFPOOL_FREE(g_icmp_connections, conn);
     }
 
-  nxmutex_unlock(&g_free_lock);
+  NET_BUFPOLL_UNLOCK(g_icmp_connections);
 }
 
 /****************************************************************************

net/icmp/icmp_sockif.c

@@ -321,7 +321,7 @@ static int icmp_getsockopt_internal(FAR struct socket *psock, int option,
 
   if (psock->s_type != SOCK_RAW)
     {
-      return ENOPROTOOPT;
+      return -ENOPROTOOPT;
     }
 
   net_lock();
@@ -383,10 +383,10 @@ static int icmp_getsockopt(FAR struct socket *psock, int level, int option,
 {
   switch (level)
   {
-    case IPPROTO_IP:
+    case SOL_IP:
       return ipv4_getsockopt(psock, option, value, value_len);
 
-    case IPPROTO_ICMP:
+    case SOL_RAW:
       return icmp_getsockopt_internal(psock, option, value, value_len);
 
     default:
@@ -429,7 +429,7 @@ static int icmp_setsockopt_internal(FAR struct socket *psock, int option,
 
   if (psock->s_type != SOCK_RAW)
     {
-      return ENOPROTOOPT;
+      return -ENOPROTOOPT;
     }
 
   net_lock();
@@ -486,10 +486,10 @@ static int icmp_setsockopt(FAR struct socket *psock, int level, int option,
 {
   switch (level)
   {
-    case IPPROTO_IP:
+    case SOL_IP:
       return ipv4_setsockopt(psock, option, value, value_len);
 
-    case IPPROTO_ICMP:
+    case SOL_RAW:
       return icmp_setsockopt_internal(psock, option, value, value_len);
 
     default:

net/icmpv6/icmpv6_conn.c

@@ -63,7 +63,6 @@ NET_BUFPOOL_DECLARE(g_icmpv6_connections, sizeof(struct icmpv6_conn_s),
                     CONFIG_NET_ICMPv6_PREALLOC_CONNS,
                     CONFIG_NET_ICMPv6_ALLOC_CONNS,
                     CONFIG_NET_ICMPv6_MAX_CONNS);
-static mutex_t g_free_lock = NXMUTEX_INITIALIZER;
 
 /* A list of all allocated IPPROTO_ICMP socket connections */
 
@@ -86,24 +85,21 @@ static dq_queue_t g_active_icmpv6_connections;
 FAR struct icmpv6_conn_s *icmpv6_alloc(void)
 {
   FAR struct icmpv6_conn_s *conn = NULL;
-  int ret;
 
   /* The free list is protected by a mutex. */
 
-  ret = nxmutex_lock(&g_free_lock);
-  if (ret >= 0)
+  NET_BUFPOLL_LOCK(g_icmpv6_connections);
+
+  conn = NET_BUFPOOL_TRYALLOC(g_icmpv6_connections);
+  if (conn != NULL)
     {
-      conn = NET_BUFPOOL_TRYALLOC(g_icmpv6_connections);
-      if (conn != NULL)
-        {
-          /* Enqueue the connection into the active list */
+      /* Enqueue the connection into the active list */
 
-          dq_addlast(&conn->sconn.node, &g_active_icmpv6_connections);
-        }
-
-      nxmutex_unlock(&g_free_lock);
+      dq_addlast(&conn->sconn.node, &g_active_icmpv6_connections);
     }
 
+  NET_BUFPOLL_UNLOCK(g_icmpv6_connections);
+
   return conn;
 }
 
@@ -124,7 +120,7 @@ void icmpv6_free(FAR struct icmpv6_conn_s *conn)
 
   /* Take the mutex (perhaps waiting) */
 
-  nxmutex_lock(&g_free_lock);
+  NET_BUFPOLL_LOCK(g_icmpv6_connections);
 
   /* Remove the connection from the active list */
 
@@ -134,7 +130,7 @@ void icmpv6_free(FAR struct icmpv6_conn_s *conn)
 
   NET_BUFPOOL_FREE(g_icmpv6_connections, conn);
 
-  nxmutex_unlock(&g_free_lock);
+  NET_BUFPOLL_UNLOCK(g_icmpv6_connections);
 }
 
 /****************************************************************************

net/icmpv6/icmpv6_sockif.c

@@ -319,7 +319,7 @@ static int icmpv6_getsockopt_internal(FAR struct socket *psock, int option,
 
   if (psock->s_type != SOCK_RAW)
     {
-      return ENOPROTOOPT;
+      return -ENOPROTOOPT;
     }
 
   net_lock();
@@ -381,10 +381,10 @@ static int icmpv6_getsockopt(FAR struct socket *psock, int level, int option,
 {
   switch (level)
     {
-      case IPPROTO_IPV6:
+      case SOL_IPV6:
         return ipv6_getsockopt(psock, option, value, value_len);
 
-      case IPPROTO_ICMPV6:
+      case SOL_ICMPV6:
         return icmpv6_getsockopt_internal(psock, option, value, value_len);
 
       default:
@@ -427,7 +427,7 @@ static int icmpv6_setsockopt_internal(FAR struct socket *psock, int option,
 
   if (psock->s_type != SOCK_RAW)
     {
-      return ENOPROTOOPT;
+      return -ENOPROTOOPT;
     }
 
   net_lock();
@@ -484,10 +484,10 @@ static int icmpv6_setsockopt(FAR struct socket *psock, int level, int option,
 {
   switch (level)
     {
-      case IPPROTO_IPV6:
+      case SOL_IPV6:
         return ipv6_setsockopt(psock, option, value, value_len);
 
-      case IPPROTO_ICMPV6:
+      case SOL_ICMPV6:
         return icmpv6_setsockopt_internal(psock, option, value, value_len);
 
       default:

net/netdev/netdev_register.c

@@ -475,7 +475,12 @@ int netdev_register(FAR struct net_driver_s *dev, enum net_lltype_e lltype)
 #ifdef CONFIG_NET_MLD
       /* Configure the device for MLD support */
 
-      mld_devinit(dev);
+      if ((flags & IFF_MULTICAST) != 0)
+        {
+          /* MLD is only supported on multicast capable devices */
+
+          mld_devinit(dev);
+        }
 #endif
 
 #ifdef NET_ICMPv6_HAVE_STACK

net/netlink/netlink_conn.c

@@ -65,7 +65,6 @@
 NET_BUFPOOL_DECLARE(g_netlink_connections, sizeof(struct netlink_conn_s),
                     CONFIG_NETLINK_PREALLOC_CONNS,
                     CONFIG_NETLINK_ALLOC_CONNS, CONFIG_NETLINK_MAX_CONNS);
-static mutex_t g_free_lock = NXMUTEX_INITIALIZER;
 
 /* A list of all allocated NetLink connections */
 
@@ -167,7 +166,7 @@ FAR struct netlink_conn_s *netlink_alloc(void)
 
   /* The free list is protected by a mutex. */
 
-  nxmutex_lock(&g_free_lock);
+  NET_BUFPOLL_LOCK(g_netlink_connections);
 
   conn = NET_BUFPOOL_TRYALLOC(g_netlink_connections);
   if (conn != NULL)
@@ -177,7 +176,7 @@ FAR struct netlink_conn_s *netlink_alloc(void)
       dq_addlast(&conn->sconn.node, &g_active_netlink_connections);
     }
 
-  nxmutex_unlock(&g_free_lock);
+  NET_BUFPOLL_UNLOCK(g_netlink_connections);
   return conn;
 }
 
@@ -198,7 +197,7 @@ void netlink_free(FAR struct netlink_conn_s *conn)
 
   DEBUGASSERT(conn->crefs == 0);
 
-  nxmutex_lock(&g_free_lock);
+  NET_BUFPOLL_LOCK(g_netlink_connections);
 
   /* Remove the connection from the active list */
 
@@ -215,7 +214,7 @@ void netlink_free(FAR struct netlink_conn_s *conn)
 
   NET_BUFPOOL_FREE(g_netlink_connections, conn);
 
-  nxmutex_unlock(&g_free_lock);
+  NET_BUFPOLL_UNLOCK(g_netlink_connections);
 }
 
 /****************************************************************************

net/pkt/pkt_conn.c

@@ -66,7 +66,6 @@
 NET_BUFPOOL_DECLARE(g_pkt_connections, sizeof(struct pkt_conn_s),
                     CONFIG_NET_PKT_PREALLOC_CONNS,
                     CONFIG_NET_PKT_ALLOC_CONNS, CONFIG_NET_PKT_MAX_CONNS);
-static mutex_t g_free_lock = NXMUTEX_INITIALIZER;
 
 /* A list of all allocated packet socket connections */
 
@@ -104,7 +103,7 @@ FAR struct pkt_conn_s *pkt_alloc(void)
 
   /* The free list is protected by a mutex. */
 
-  nxmutex_lock(&g_free_lock);
+  NET_BUFPOLL_LOCK(g_pkt_connections);
 
   conn = NET_BUFPOOL_TRYALLOC(g_pkt_connections);
   if (conn)
@@ -114,7 +113,7 @@ FAR struct pkt_conn_s *pkt_alloc(void)
       dq_addlast(&conn->sconn.node, &g_active_pkt_connections);
     }
 
-  nxmutex_unlock(&g_free_lock);
+  NET_BUFPOLL_UNLOCK(g_pkt_connections);
   return conn;
 }
 
@@ -133,7 +132,7 @@ void pkt_free(FAR struct pkt_conn_s *conn)
 
   DEBUGASSERT(conn->crefs == 0);
 
-  nxmutex_lock(&g_free_lock);
+  NET_BUFPOLL_LOCK(g_pkt_connections);
 
   /* Remove the connection from the active list */
 
@@ -143,7 +142,7 @@ void pkt_free(FAR struct pkt_conn_s *conn)
 
   NET_BUFPOOL_FREE(g_pkt_connections, conn);
 
-  nxmutex_unlock(&g_free_lock);
+  NET_BUFPOLL_UNLOCK(g_pkt_connections);
 }
 
 /****************************************************************************

net/udp/udp_conn.c

@@ -91,7 +91,6 @@
 NET_BUFPOOL_DECLARE(g_udp_connections, sizeof(struct udp_conn_s),
                     CONFIG_NET_UDP_PREALLOC_CONNS,
                     CONFIG_NET_UDP_ALLOC_CONNS, CONFIG_NET_UDP_MAX_CONNS);
-static mutex_t g_free_lock = NXMUTEX_INITIALIZER;
 
 /* A list of all allocated UDP connections */
 
@@ -566,7 +565,7 @@ FAR struct udp_conn_s *udp_alloc(uint8_t domain)
 
   /* The free list is protected by a mutex. */
 
-  nxmutex_lock(&g_free_lock);
+  NET_BUFPOLL_LOCK(g_udp_connections);
 
   conn = NET_BUFPOOL_TRYALLOC(g_udp_connections);
 
@@ -599,7 +598,7 @@ FAR struct udp_conn_s *udp_alloc(uint8_t domain)
       dq_addlast(&conn->sconn.node, &g_active_udp_connections);
     }
 
-  nxmutex_unlock(&g_free_lock);
+  NET_BUFPOLL_UNLOCK(g_udp_connections);
   return conn;
 }
 
@@ -622,7 +621,7 @@ void udp_free(FAR struct udp_conn_s *conn)
 
   DEBUGASSERT(conn->crefs == 0);
 
-  nxmutex_lock(&g_free_lock);
+  NET_BUFPOLL_LOCK(g_udp_connections);
   conn->lport = 0;
 
   /* Remove the connection from the active list */
@@ -654,7 +653,7 @@ void udp_free(FAR struct udp_conn_s *conn)
 
   NET_BUFPOOL_FREE(g_udp_connections, conn);
 
-  nxmutex_unlock(&g_free_lock);
+  NET_BUFPOLL_UNLOCK(g_udp_connections);
 }
 
 /****************************************************************************

net/usrsock/usrsock_conn.c

@@ -63,7 +63,6 @@ NET_BUFPOOL_DECLARE(g_usrsock_connections, sizeof(struct usrsock_conn_s),
                     CONFIG_NET_USRSOCK_PREALLOC_CONNS,
                     CONFIG_NET_USRSOCK_ALLOC_CONNS,
                     CONFIG_NET_USRSOCK_MAX_CONNS);
-static mutex_t g_free_lock = NXMUTEX_INITIALIZER;
 
 /* A list of all allocated usrsock connections */
 
@@ -88,7 +87,7 @@ FAR struct usrsock_conn_s *usrsock_alloc(void)
 
   /* The free list is protected by a a mutex. */
 
-  nxmutex_lock(&g_free_lock);
+  NET_BUFPOLL_LOCK(g_usrsock_connections);
 
   conn = NET_BUFPOOL_TRYALLOC(g_usrsock_connections);
   if (conn)
@@ -104,7 +103,7 @@ FAR struct usrsock_conn_s *usrsock_alloc(void)
       dq_addlast(&conn->sconn.node, &g_active_usrsock_connections);
     }
 
-  nxmutex_unlock(&g_free_lock);
+  NET_BUFPOLL_UNLOCK(g_usrsock_connections);
   return conn;
 }
 
@@ -123,7 +122,7 @@ void usrsock_free(FAR struct usrsock_conn_s *conn)
 
   DEBUGASSERT(conn->crefs == 0);
 
-  nxmutex_lock(&g_free_lock);
+  NET_BUFPOLL_LOCK(g_usrsock_connections);
 
   /* Remove the connection from the active list */
 
@@ -137,7 +136,7 @@ void usrsock_free(FAR struct usrsock_conn_s *conn)
 
   NET_BUFPOOL_FREE(g_usrsock_connections, conn);
 
-  nxmutex_unlock(&g_free_lock);
+  NET_BUFPOLL_UNLOCK(g_usrsock_connections);
 }
 
 /****************************************************************************

net/utils/net_bufpool.c

@@ -98,6 +98,7 @@ FAR void *net_bufpool_timedalloc(FAR struct net_bufpool_s *pool,
                                  unsigned int timeout)
 {
   FAR struct net_bufnode_s *node;
+  FAR void *buf;
   int ret;
   int i;
 
@@ -121,6 +122,8 @@ FAR void *net_bufpool_timedalloc(FAR struct net_bufpool_s *pool,
       return NULL;
     }
 
+  nxrmutex_lock(&pool->lock);
+
   /* If we get here, then we didn't exceed maxalloc. */
 
   if (pool->dynalloc > 0 && sq_peek(&pool->freebuffers) == NULL)
@@ -128,7 +131,8 @@ FAR void *net_bufpool_timedalloc(FAR struct net_bufpool_s *pool,
       node = kmm_zalloc(pool->nodesize * pool->dynalloc);
       if (node == NULL)
         {
-          return NULL;
+          buf = NULL;
+          goto out;
         }
 
       /* Now initialize each connection structure */
@@ -141,7 +145,11 @@ FAR void *net_bufpool_timedalloc(FAR struct net_bufpool_s *pool,
         }
     }
 
-  return sq_remfirst(&pool->freebuffers);
+  buf = sq_remfirst(&pool->freebuffers);
+
+out:
+  nxrmutex_unlock(&pool->lock);
+  return buf;
 }
 
 /****************************************************************************
@@ -170,12 +178,16 @@ void net_bufpool_free(FAR struct net_bufpool_s *pool, FAR void *node)
     {
       FAR struct net_bufnode_s *net_bufnode = node;
 
+      net_bufpool_lock(pool);
+
       /* Set the buffer to zero, to make sure all nodes in the free buffer
        * pool are zeroed.
        */
 
       memset(net_bufnode, 0, pool->nodesize);
       sq_addlast(&net_bufnode->node, &pool->freebuffers);
+
+      net_bufpool_unlock(pool);
     }
 
   nxsem_post(&pool->sem);
@@ -205,3 +217,60 @@ int net_bufpool_test(FAR struct net_bufpool_s *pool)
 
   return ret;
 }
+
+/****************************************************************************
+ * Name: net_bufpool_navail
+ *
+ * Description:
+ *   Return the number of available buffers in the buffer pool.
+ *
+ * Assumptions:
+ *   None.
+ *
+ ****************************************************************************/
+
+int net_bufpool_navail(FAR struct net_bufpool_s *pool)
+{
+  int val = 0;
+  int ret;
+
+  ret = nxsem_get_value(&pool->sem, &val);
+  if (ret >= 0)
+    {
+      ret = val;
+    }
+
+  return ret;
+}
+
+/****************************************************************************
+ * Name: net_bufpool_lock
+ *
+ * Description:
+ *   Use the bufpool lock to protect the node of the buffer pool.
+ *
+ * Input Parameters:
+ *   pool - The lock of pool to be locked.
+ *
+ ****************************************************************************/
+
+void net_bufpool_lock(FAR struct net_bufpool_s *pool)
+{
+  nxrmutex_lock(&pool->lock);
+}
+
+/****************************************************************************
+ * Name: net_bufpool_unlock
+ *
+ * Description:
+ *   Finish using the bufpool lock to protect the node of the buffer pool.
+ *
+ * Input Parameters:
+ *   pool - The lock of pool to be unlocked.
+ *
+ ****************************************************************************/
+
+void net_bufpool_unlock(FAR struct net_bufpool_s *pool)
+{
+  nxrmutex_unlock(&pool->lock);
+}

net/utils/utils.h

@@ -97,6 +97,7 @@
       dynalloc, \
       -(int)(nodesize), \
       SEM_INITIALIZER(NET_BUFPOOL_MAX(prealloc, dynalloc, maxalloc)), \
+      NXRMUTEX_INITIALIZER, \
       { NULL, NULL } \
     };
 
@@ -105,6 +106,9 @@
 #define NET_BUFPOOL_ALLOC(p)        net_bufpool_timedalloc(&p, UINT_MAX)
 #define NET_BUFPOOL_FREE(p,n)       net_bufpool_free(&p, n)
 #define NET_BUFPOOL_TEST(p)         net_bufpool_test(&p)
+#define NET_BUFPOOL_NAVAIL(p)       net_bufpool_navail(&p)
+#define NET_BUFPOLL_LOCK(p)         net_bufpool_lock(&p)
+#define NET_BUFPOLL_UNLOCK(p)       net_bufpool_unlock(&p)
 
 /****************************************************************************
  * Public Types
@@ -132,6 +136,7 @@ struct net_bufpool_s
 
   sem_t      sem;      /* The semaphore for waiting for free buffers */
 
+  rmutex_t   lock;     /* The lock for the pool */
   sq_queue_t freebuffers;
 };
 
@@ -415,6 +420,45 @@ void net_bufpool_free(FAR struct net_bufpool_s *pool, FAR void *node);
 
 int net_bufpool_test(FAR struct net_bufpool_s *pool);
 
+/****************************************************************************
+ * Name: net_bufpool_navail
+ *
+ * Description:
+ *   Return the number of available buffers in the buffer pool.
+ *
+ * Assumptions:
+ *   None.
+ *
+ ****************************************************************************/
+
+int net_bufpool_navail(FAR struct net_bufpool_s *pool);
+
+/****************************************************************************
+ * Name: net_bufpool_lock
+ *
+ * Description:
+ *   Use the bufpool lock to protect the node of the buffer pool.
+ *
+ * Input Parameters:
+ *   pool - The lock of pool to be locked.
+ *
+ ****************************************************************************/
+
+void net_bufpool_lock(FAR struct net_bufpool_s *pool);
+
+/****************************************************************************
+ * Name: net_bufpool_unlock
+ *
+ * Description:
+ *   Finish using the bufpool lock to protect the node of the buffer pool.
+ *
+ * Input Parameters:
+ *   pool - The lock of pool to be unlocked.
+ *
+ ****************************************************************************/
+
+void net_bufpool_unlock(FAR struct net_bufpool_s *pool);
+
 /****************************************************************************
  * Name: net_chksum_adjust
  *