Fix wait loop and void cast (#24)

* Simplify EINTR/ECANCEL error handling

1. Add semaphore uninterruptible wait function
2 .Replace semaphore wait loop with a single uninterruptible wait
3. Replace all sem_xxx to nxsem_xxx

* Unify the void cast usage

1. Remove void cast for function because many place ignore the returned value witout cast
2. Replace void cast for variable with UNUSED macro

arch/arm/src/a1x/a1x_irq.c

@@ -156,7 +156,7 @@ void up_irqinitialize(void)
     {
       putreg32(0x00000000, A1X_INTC_EN(i));   /* 0 disables corresponding interrupt */
       putreg32(0xffffffff, A1X_INTC_MASK(i)); /* 1 masks corresponding interrupt */
-      (void)getreg32(A1X_INTC_IRQ_PEND(i));   /* Reading status clears pending interrupts */
+      getreg32(A1X_INTC_IRQ_PEND(i));         /* Reading status clears pending interrupts */
     }
 
   /* Set the interrupt base address to zero.  We do not use the vectored
@@ -178,7 +178,7 @@ void up_irqinitialize(void)
 
   /* And finally, enable interrupts */
 
-  (void)up_irq_enable();
+  up_irq_enable();
 #endif
 
   a1x_dumpintc("initial", 0);

arch/arm/src/a1x/a1x_pio.c

@@ -163,7 +163,7 @@ static int a1x_pio_interrupt(int irq, void *context)
             {
               /* Yes.. dispatch the interrupt */
 
-              (void)arm_doirq(irq, regs);
+              arm_doirq(irq, regs);
             }
 
           irq++;

arch/arm/src/a1x/a1x_serial.c

@@ -1528,31 +1528,31 @@ void up_earlyserialinit(void)
 void up_serialinit(void)
 {
 #ifdef CONSOLE_DEV
-  (void)uart_register("/dev/console", &CONSOLE_DEV);
+  uart_register("/dev/console", &CONSOLE_DEV);
 #endif
 #ifdef TTYS0_DEV
-  (void)uart_register("/dev/ttyS0", &TTYS0_DEV);
+  uart_register("/dev/ttyS0", &TTYS0_DEV);
 #endif
 #ifdef TTYS1_DEV
-  (void)uart_register("/dev/ttyS1", &TTYS1_DEV);
+  uart_register("/dev/ttyS1", &TTYS1_DEV);
 #endif
 #ifdef TTYS2_DEV
-  (void)uart_register("/dev/ttyS2", &TTYS2_DEV);
+  uart_register("/dev/ttyS2", &TTYS2_DEV);
 #endif
 #ifdef TTYS3_DEV
-  (void)uart_register("/dev/ttyS3", &TTYS3_DEV);
+  uart_register("/dev/ttyS3", &TTYS3_DEV);
 #endif
 #ifdef TTYS4_DEV
-  (void)uart_register("/dev/ttyS4", &TTYS4_DEV);
+  uart_register("/dev/ttyS4", &TTYS4_DEV);
 #endif
 #ifdef TTYS5_DEV
-  (void)uart_register("/dev/ttyS5", &TTYS5_DEV);
+  uart_register("/dev/ttyS5", &TTYS5_DEV);
 #endif
 #ifdef TTYS6_DEV
-  (void)uart_register("/dev/ttyS6", &TTYS6_DEV);
+  uart_register("/dev/ttyS6", &TTYS6_DEV);
 #endif
 #ifdef TTYS7_DEV
-  (void)uart_register("/dev/ttyS7", &TTYS7_DEV);
+  uart_register("/dev/ttyS7", &TTYS7_DEV);
 #endif
 }
 

arch/arm/src/a1x/a1x_timerisr.c

@@ -138,7 +138,7 @@ void arm_timer_initialize(void)
 
   /* Attach the timer interrupt vector */
 
-  (void)irq_attach(A1X_IRQ_TIMER0, (xcpt_t)a1x_timerisr, NULL);
+  irq_attach(A1X_IRQ_TIMER0, (xcpt_t)a1x_timerisr, NULL);
 
   /* Enable interrupts from the TIMER 0 port */
 

arch/arm/src/am335x/am335x_gpioirq.c

@@ -259,7 +259,7 @@ void am335x_gpio_irqinitialize(void)
 
   /* Attach and enable the GPIO0 IRQ */
 
-  (void)irq_attach(AM335X_IRQ_GPIO0A, am335x_gpio0_interrupt, NULL);
+  irq_attach(AM335X_IRQ_GPIO0A, am335x_gpio0_interrupt, NULL);
   up_enable_irq(AM335X_IRQ_GPIO0A);
 #endif
 
@@ -284,7 +284,7 @@ void am335x_gpio_irqinitialize(void)
 
   /* Attach and enable the GPIO1 IRQ */
 
-  (void)irq_attach(AM335X_IRQ_GPIO1A, am335x_gpio1_interrupt, NULL);
+  irq_attach(AM335X_IRQ_GPIO1A, am335x_gpio1_interrupt, NULL);
   up_enable_irq(AM335X_IRQ_GPIO1A);
 #endif
 
@@ -309,7 +309,7 @@ void am335x_gpio_irqinitialize(void)
 
   /* Attach and enable the GPIO2 IRQ */
 
-  (void)irq_attach(AM335X_IRQ_GPIO2A, am335x_gpio2_interrupt, NULL);
+  irq_attach(AM335X_IRQ_GPIO2A, am335x_gpio2_interrupt, NULL);
   up_enable_irq(AM335X_IRQ_GPIO2A);
 #endif
 
@@ -334,7 +334,7 @@ void am335x_gpio_irqinitialize(void)
 
   /* Attach and enable the GPIO3 IRQ */
 
-  (void)irq_attach(AM335X_IRQ_GPIO3A, am335x_gpio3_interrupt, NULL);
+  irq_attach(AM335X_IRQ_GPIO3A, am335x_gpio3_interrupt, NULL);
   up_enable_irq(AM335X_IRQ_GPIO3A);
 #endif
 }

arch/arm/src/am335x/am335x_irq.c

@@ -131,8 +131,8 @@ void up_irqinitialize(void)
   for (i = 0; i < AM335X_IRQ_NINT; i += 32)
     {
       putreg32(0xffffffff, AM335X_INTC_MIR_SET(i)); /* 1 masks corresponding interrupt */
-      (void)getreg32(AM335X_INTC_PEND_IRQ(i));   /* Reading status clears pending interrupts */
-      (void)getreg32(AM335X_INTC_PEND_FIQ(i));   /* Reading status clears pending interrupts */
+      getreg32(AM335X_INTC_PEND_IRQ(i));   /* Reading status clears pending interrupts */
+      getreg32(AM335X_INTC_PEND_FIQ(i));   /* Reading status clears pending interrupts */
     }
 
   /* currents_regs is non-NULL only while processing an interrupt */
@@ -150,7 +150,7 @@ void up_irqinitialize(void)
 
   /* And finally, enable interrupts */
 
-  (void)up_irq_enable();
+  up_irq_enable();
 #endif
 }
 

arch/arm/src/am335x/am335x_lcdc.c

@@ -585,7 +585,7 @@ int am335x_lcd_initialize(FAR const struct am335x_panel_info_s *panel)
 
   /* Initialize the device state singleton */
 
-  sem_init(&priv->exclsem, 0, 1);
+  nxsem_init(&priv->exclsem, 0, 1);
   memcpy(&priv->panel, panel, sizeof(struct am335x_panel_info_s));
 
   /* Save framebuffer information */

arch/arm/src/am335x/am335x_serial.c

@@ -1347,25 +1347,25 @@ void up_earlyserialinit(void)
 void up_serialinit(void)
 {
 #ifdef CONSOLE_DEV
-  (void)uart_register("/dev/console", &CONSOLE_DEV);
+  uart_register("/dev/console", &CONSOLE_DEV);
 #endif
 #ifdef TTYS0_DEV
-  (void)uart_register("/dev/ttyS0", &TTYS0_DEV);
+  uart_register("/dev/ttyS0", &TTYS0_DEV);
 #endif
 #ifdef TTYS1_DEV
-  (void)uart_register("/dev/ttyS1", &TTYS1_DEV);
+  uart_register("/dev/ttyS1", &TTYS1_DEV);
 #endif
 #ifdef TTYS2_DEV
-  (void)uart_register("/dev/ttyS2", &TTYS2_DEV);
+  uart_register("/dev/ttyS2", &TTYS2_DEV);
 #endif
 #ifdef TTYS3_DEV
-  (void)uart_register("/dev/ttyS3", &TTYS3_DEV);
+  uart_register("/dev/ttyS3", &TTYS3_DEV);
 #endif
 #ifdef TTYS4_DEV
-  (void)uart_register("/dev/ttyS4", &TTYS4_DEV);
+  uart_register("/dev/ttyS4", &TTYS4_DEV);
 #endif
 #ifdef TTYS5_DEV
-  (void)uart_register("/dev/ttyS5", &TTYS5_DEV);
+  uart_register("/dev/ttyS5", &TTYS5_DEV);
 #endif
 }
 

arch/arm/src/am335x/am335x_timerisr.c

@@ -154,7 +154,7 @@ void arm_timer_initialize(void)
 
   /* Attach the timer interrupt vector */
 
-  (void)irq_attach(AM335X_IRQ_TIMER1_1MS, (xcpt_t)am335x_timerisr, NULL);
+  irq_attach(AM335X_IRQ_TIMER1_1MS, (xcpt_t)am335x_timerisr, NULL);
 
   /* Clear interrupt status */
 
@@ -193,7 +193,7 @@ void arm_timer_initialize(void)
 
   /* Attach the timer interrupt vector */
 
-  (void)irq_attach(AM335X_IRQ_TIMER2, (xcpt_t)am335x_timerisr, NULL);
+  irq_attach(AM335X_IRQ_TIMER2, (xcpt_t)am335x_timerisr, NULL);
 
   /* Enable overflow interrupt */
 

arch/arm/src/arm/up_assert.c

@@ -290,7 +290,7 @@ static void up_dumpstate(void)
 #ifdef CONFIG_ARCH_USBDUMP
   /* Dump USB trace data */
 
-  (void)usbtrace_enumerate(assert_tracecallback, NULL);
+  usbtrace_enumerate(assert_tracecallback, NULL);
 #endif
 }
 #else
@@ -306,13 +306,13 @@ static void _up_assert(int errorcode)
 {
   /* Flush any buffered SYSLOG data */
 
-  (void)syslog_flush();
+  syslog_flush();
 
   /* Are we in an interrupt handler or the idle task? */
 
   if (CURRENT_REGS || running_task()->flink == NULL)
     {
-      (void)up_irq_save();
+      up_irq_save();
       for (; ; )
         {
 #if CONFIG_BOARD_RESET_ON_ASSERT >= 1
@@ -353,7 +353,7 @@ void up_assert(const uint8_t *filename, int lineno)
 
   /* Flush any buffered SYSLOG data (prior to the assertion) */
 
-  (void)syslog_flush();
+  syslog_flush();
 
 #if CONFIG_TASK_NAME_SIZE > 0
   _alert("Assertion failed at file:%s line: %d task: %s\n",
@@ -367,7 +367,7 @@ void up_assert(const uint8_t *filename, int lineno)
 
   /* Flush any buffered SYSLOG data (from the above) */
 
-  (void)syslog_flush();
+  syslog_flush();
 
 #ifdef CONFIG_BOARD_CRASHDUMP
   board_crashdump(up_getsp(), running_task(), filename, lineno);

arch/arm/src/arm/up_blocktask.c

@@ -161,7 +161,7 @@ void up_block_task(struct tcb_s *tcb, tstate_t task_state)
            * thread at the head of the ready-to-run list.
            */
 
-          (void)group_addrenv(rtcb);
+          group_addrenv(rtcb);
 #endif
           /* Reset scheduler parameters */
 

arch/arm/src/arm/up_doirq.c

@@ -119,7 +119,7 @@ void up_doirq(int irq, uint32_t *regs)
        * thread at the head of the ready-to-run list.
        */
 
-      (void)group_addrenv(NULL);
+      group_addrenv(NULL);
 #endif
     }
 #endif

arch/arm/src/arm/up_releasepending.c

@@ -130,7 +130,7 @@ void up_release_pending(void)
            * thread at the head of the ready-to-run list.
            */
 
-          (void)group_addrenv(rtcb);
+          group_addrenv(rtcb);
 #endif
           /* Update scheduler parameters */
 

arch/arm/src/arm/up_reprioritizertr.c

@@ -183,7 +183,7 @@ void up_reprioritize_rtr(struct tcb_s *tcb, uint8_t priority)
                * thread at the head of the ready-to-run list.
                */
 
-              (void)group_addrenv(rtcb);
+              group_addrenv(rtcb);
 #endif
               /* Update scheduler parameters */
 

arch/arm/src/arm/up_sigdeliver.c

@@ -107,7 +107,7 @@ void up_sigdeliver(void)
    */
 
   sinfo("Resuming\n");
-  (void)up_irq_save();
+  up_irq_save();
   rtcb->pterrno       = saved_errno;
 
   /* Modify the saved return state with the actual saved values in the

arch/arm/src/arm/up_unblocktask.c

@@ -145,7 +145,7 @@ void up_unblock_task(struct tcb_s *tcb)
            * thread at the head of the ready-to-run list.
            */
 
-          (void)group_addrenv(rtcb);
+          group_addrenv(rtcb);
 #endif
           /* Update scheduler parameters */
 

arch/arm/src/armv6-m/up_assert.c

@@ -347,7 +347,7 @@ static void up_dumpstate(void)
 #ifdef CONFIG_ARCH_USBDUMP
   /* Dump USB trace data */
 
-  (void)usbtrace_enumerate(assert_tracecallback, NULL);
+  usbtrace_enumerate(assert_tracecallback, NULL);
 #endif
 }
 #else
@@ -363,13 +363,13 @@ static void _up_assert(int errorcode)
 {
   /* Flush any buffered SYSLOG data */
 
-  (void)syslog_flush();
+  syslog_flush();
 
   /* Are we in an interrupt handler or the idle task? */
 
   if (CURRENT_REGS || running_task()->flink == NULL)
     {
-      (void)up_irq_save();
+      up_irq_save();
       for (; ; )
         {
 #if CONFIG_BOARD_RESET_ON_ASSERT >= 1
@@ -410,7 +410,7 @@ void up_assert(const uint8_t *filename, int lineno)
 
   /* Flush any buffered SYSLOG data (prior to the assertion) */
 
-  (void)syslog_flush();
+  syslog_flush();
 
 #if CONFIG_TASK_NAME_SIZE > 0
   _alert("Assertion failed at file:%s line: %d task: %s\n",
@@ -424,7 +424,7 @@ void up_assert(const uint8_t *filename, int lineno)
 
   /* Flush any buffered SYSLOG data (from the above) */
 
-  (void)syslog_flush();
+  syslog_flush();
 
 #ifdef CONFIG_BOARD_CRASHDUMP
   board_crashdump(up_getsp(), running_task(), filename, lineno);

arch/arm/src/armv6-m/up_hardfault.c

@@ -134,7 +134,7 @@ int up_hardfault(int irq, FAR void *context, FAR void *arg)
           getprimask(), getipsr());
 #endif
 
-  (void)up_irq_save();
+  up_irq_save();
   hfalert("PANIC!!! Hard fault\n");
   PANIC();
   return OK; /* Won't get here */

arch/arm/src/armv6-m/up_sigdeliver.c

@@ -111,7 +111,7 @@ void up_sigdeliver(void)
    */
 
   sinfo("Resuming\n");
-  (void)up_irq_save();
+  up_irq_save();
   rtcb->pterrno = saved_errno;
 
   /* Modify the saved return state with the actual saved values in the

arch/arm/src/armv6-m/up_signal_dispatch.c

@@ -84,8 +84,8 @@ void up_signal_dispatch(_sa_sigaction_t sighand, int signo,
 {
   /* Let sys_call4() do all of the work */
 
-  (void)sys_call4(SYS_signal_handler, (uintptr_t)sighand, (uintptr_t)signo,
-                  (uintptr_t)info, (uintptr_t)ucontext);
+  sys_call4(SYS_signal_handler, (uintptr_t)sighand, (uintptr_t)signo,
+            (uintptr_t)info, (uintptr_t)ucontext);
 }
 
 #endif /* (CONFIG_BUILD_PROTECTED || CONFIG_BUILD_KERNEL) && !CONFIG_DISABLE_PTHREAD */

arch/arm/src/armv7-a/arm_assert.c

@@ -375,7 +375,7 @@ static void up_dumpstate(void)
 #ifdef CONFIG_ARCH_USBDUMP
   /* Dump USB trace data */
 
-  (void)usbtrace_enumerate(assert_tracecallback, NULL);
+  usbtrace_enumerate(assert_tracecallback, NULL);
 #endif
 }
 #else
@@ -391,7 +391,7 @@ static void _up_assert(int errorcode)
 {
   /* Flush any buffered SYSLOG data */
 
-  (void)syslog_flush();
+  syslog_flush();
 
   /* Are we in an interrupt handler or the idle task? */
 
@@ -399,14 +399,14 @@ static void _up_assert(int errorcode)
     {
       /* Disable interrupts on this CPU */
 
-      (void)up_irq_save();
+      up_irq_save();
 
       for (; ; )
         {
 #ifdef CONFIG_SMP
           /* Try (again) to stop activity on other CPUs */
 
-          (void)spin_trylock(&g_cpu_irqlock);
+          spin_trylock(&g_cpu_irqlock);
 #endif
 
 #if CONFIG_BOARD_RESET_ON_ASSERT >= 1
@@ -449,7 +449,7 @@ void up_assert(const uint8_t *filename, int lineno)
 
   /* Flush any buffered SYSLOG data (prior to the assertion) */
 
-  (void)syslog_flush();
+  syslog_flush();
 
 #ifdef CONFIG_SMP
 #if CONFIG_TASK_NAME_SIZE > 0
@@ -473,7 +473,7 @@ void up_assert(const uint8_t *filename, int lineno)
 
   /* Flush any buffered SYSLOG data (from the above) */
 
-  (void)syslog_flush();
+  syslog_flush();
 
 #ifdef CONFIG_BOARD_CRASHDUMP
   board_crashdump(up_getsp(), running_task(), filename, lineno);

arch/arm/src/armv7-a/arm_blocktask.c

@@ -182,7 +182,7 @@ void up_block_task(struct tcb_s *tcb, tstate_t task_state)
            * thread at the head of the ready-to-run list.
            */
 
-          (void)group_addrenv(rtcb);
+          group_addrenv(rtcb);
 #endif
           /* Reset scheduler parameters */
 

arch/arm/src/armv7-a/arm_doirq.c

@@ -118,7 +118,7 @@ static inline uint32_t *_arm_doirq(int irq, uint32_t *regs)
        * thread at the head of the ready-to-run list.
        */
 
-      (void)group_addrenv(NULL);
+      group_addrenv(NULL);
 #endif
     }
 #endif

arch/arm/src/armv7-a/arm_pgalloc.c

@@ -163,7 +163,7 @@ static int get_pgtable(FAR group_addrenv_t *addrenv, uintptr_t vaddr)
 
           /* And instantiate the modified environment */
 
-          (void)up_addrenv_select(addrenv, NULL);
+          up_addrenv_select(addrenv, NULL);
         }
     }
 

arch/arm/src/armv7-a/arm_releasepending.c

@@ -150,7 +150,7 @@ void up_release_pending(void)
            * thread at the head of the ready-to-run list.
            */
 
-          (void)group_addrenv(rtcb);
+          group_addrenv(rtcb);
 #endif
           /* Update scheduler parameters */
 

arch/arm/src/armv7-a/arm_reprioritizertr.c

@@ -204,7 +204,7 @@ void up_reprioritize_rtr(struct tcb_s *tcb, uint8_t priority)
                * thread at the head of the ready-to-run list.
                */
 
-              (void)group_addrenv(rtcb);
+              group_addrenv(rtcb);
 #endif
               /* Update scheduler parameters */
 

arch/arm/src/armv7-a/arm_sigdeliver.c

@@ -152,9 +152,9 @@ void up_sigdeliver(void)
    */
 
 #ifdef CONFIG_SMP
-  (void)enter_critical_section();
+  enter_critical_section();
 #else
-  (void)up_irq_save();
+  up_irq_save();
 #endif
 
   /* Restore the saved errno value */
@@ -187,7 +187,7 @@ void up_sigdeliver(void)
   DEBUGASSERT(rtcb->irqcount == 1);
   while (rtcb->irqcount < saved_irqcount)
     {
-      (void)enter_critical_section();
+      enter_critical_section();
     }
 #endif
 

arch/arm/src/armv7-a/arm_signal_dispatch.c

@@ -93,8 +93,8 @@ void up_signal_dispatch(_sa_sigaction_t sighand, int signo,
     {
       /* Yes.. Let sys_call4() do all of the work to get us into user space */
 
-      (void)sys_call4(SYS_signal_handler, (uintptr_t)sighand, (uintptr_t)signo,
-                      (uintptr_t)info, (uintptr_t)ucontext);
+      sys_call4(SYS_signal_handler, (uintptr_t)sighand, (uintptr_t)signo,
+                (uintptr_t)info, (uintptr_t)ucontext);
     }
   else
     {

arch/arm/src/armv7-a/arm_unblocktask.c

@@ -166,7 +166,7 @@ void up_unblock_task(struct tcb_s *tcb)
            * thread at the head of the ready-to-run list.
            */
 
-          (void)group_addrenv(rtcb);
+          group_addrenv(rtcb);
 #endif
           /* Update scheduler parameters */
 

arch/arm/src/armv7-m/up_assert.c

@@ -369,7 +369,7 @@ static void up_dumpstate(void)
 #ifdef CONFIG_ARCH_USBDUMP
   /* Dump USB trace data */
 
-  (void)usbtrace_enumerate(assert_tracecallback, NULL);
+  usbtrace_enumerate(assert_tracecallback, NULL);
 #endif
 }
 #else
@@ -385,19 +385,19 @@ static void _up_assert(int errorcode)
 {
   /* Flush any buffered SYSLOG data */
 
-  (void)syslog_flush();
+  syslog_flush();
 
   /* Are we in an interrupt handler or the idle task? */
 
   if (CURRENT_REGS || (running_task())->flink == NULL)
     {
-      (void)up_irq_save();
+      up_irq_save();
       for (; ; )
         {
 #ifdef CONFIG_SMP
           /* Try (again) to stop activity on other CPUs */
 
-          (void)spin_trylock(&g_cpu_irqlock);
+          spin_trylock(&g_cpu_irqlock);
 #endif
 
 #if CONFIG_BOARD_RESET_ON_ASSERT >= 1
@@ -438,7 +438,7 @@ void up_assert(const uint8_t *filename, int lineno)
 
   /* Flush any buffered SYSLOG data (prior to the assertion) */
 
-  (void)syslog_flush();
+  syslog_flush();
 
 #ifdef CONFIG_SMP
 #if CONFIG_TASK_NAME_SIZE > 0
@@ -462,7 +462,7 @@ void up_assert(const uint8_t *filename, int lineno)
 
   /* Flush any buffered SYSLOG data (from the above) */
 
-  (void)syslog_flush();
+  syslog_flush();
 
 #ifdef CONFIG_BOARD_CRASHDUMP
   board_crashdump(up_getsp(), running_task(), filename, lineno);

arch/arm/src/armv7-m/up_hardfault.c

@@ -143,7 +143,7 @@ int up_hardfault(int irq, FAR void *context, FAR void *arg)
           getreg32(NVIC_DFAULTS), getreg32(NVIC_BFAULT_ADDR),
           getreg32(NVIC_AFAULTS));
 
-  (void)up_irq_save();
+  up_irq_save();
   _alert("PANIC!!! Hard fault: %08x\n", getreg32(NVIC_HFAULTS));
   PANIC();
   return OK;

arch/arm/src/armv7-m/up_itm_syslog.c

@@ -186,7 +186,7 @@ void itm_syslog_initialize(void)
 
   /* Setup the SYSLOG channel */
 
-  (void)syslog_channel(&g_itm_channel);
+  syslog_channel(&g_itm_channel);
 }
 
 #endif /* CONFIG_ARMV7M_ITMSYSLOG */

arch/arm/src/armv7-m/up_memfault.c

@@ -79,7 +79,7 @@ int up_memfault(int irq, FAR void *context, FAR void *arg)
 {
   /* Dump some memory management fault info */
 
-  (void)up_irq_save();
+  up_irq_save();
   _alert("PANIC!!! Memory Management Fault:\n");
   mfinfo("  IRQ: %d context: %p\n", irq, context);
   _alert("  CFAULTS: %08x MMFAR: %08x\n",

arch/arm/src/armv7-m/up_sigdeliver.c

@@ -156,9 +156,9 @@ void up_sigdeliver(void)
    */
 
 #ifdef CONFIG_SMP
-  (void)enter_critical_section();
+  enter_critical_section();
 #else
-  (void)up_irq_save();
+  up_irq_save();
 #endif
 
   /* Restore the saved errno value */
@@ -199,7 +199,7 @@ void up_sigdeliver(void)
   DEBUGASSERT(rtcb->irqcount == 1);
   while (rtcb->irqcount < saved_irqcount)
     {
-      (void)enter_critical_section();
+      enter_critical_section();
     }
 #endif
 

arch/arm/src/armv7-m/up_signal_dispatch.c

@@ -84,8 +84,8 @@ void up_signal_dispatch(_sa_sigaction_t sighand, int signo,
 {
   /* Let sys_call4() do all of the work */
 
-  (void)sys_call4(SYS_signal_handler, (uintptr_t)sighand, (uintptr_t)signo,
-                  (uintptr_t)info, (uintptr_t)ucontext);
+  sys_call4(SYS_signal_handler, (uintptr_t)sighand, (uintptr_t)signo,
+            (uintptr_t)info, (uintptr_t)ucontext);
 }
 
 #endif /* (CONFIG_BUILD_PROTECTED || CONFIG_BUILD_KERNEL) && !CONFIG_DISABLE_PTHREAD */

arch/arm/src/armv7-r/arm_assert.c

@@ -354,7 +354,7 @@ static void up_dumpstate(void)
 #ifdef CONFIG_ARCH_USBDUMP
   /* Dump USB trace data */
 
-  (void)usbtrace_enumerate(assert_tracecallback, NULL);
+  usbtrace_enumerate(assert_tracecallback, NULL);
 #endif
 }
 #else
@@ -370,13 +370,13 @@ static void _up_assert(int errorcode)
 {
   /* Flush any buffered SYSLOG data */
 
-  (void)syslog_flush();
+  syslog_flush();
 
   /* Are we in an interrupt handler or the idle task? */
 
   if (CURRENT_REGS || (running_task())->flink == NULL)
     {
-      (void)up_irq_save();
+      up_irq_save();
       for (; ; )
         {
 #if CONFIG_BOARD_RESET_ON_ASSERT >= 1
@@ -417,7 +417,7 @@ void up_assert(const uint8_t *filename, int lineno)
 
   /* Flush any buffered SYSLOG data (prior to the assertion) */
 
-  (void)syslog_flush();
+  syslog_flush();
 
 #if CONFIG_TASK_NAME_SIZE > 0
   _alert("Assertion failed at file:%s line: %d task: %s\n",
@@ -431,7 +431,7 @@ void up_assert(const uint8_t *filename, int lineno)
 
   /* Flush any buffered SYSLOG data (from the above) */
 
-  (void)syslog_flush();
+  syslog_flush();
 
 #ifdef CONFIG_BOARD_CRASHDUMP
   board_crashdump(up_getsp(), running_task(), filename, lineno);

arch/arm/src/armv7-r/arm_sigdeliver.c

@@ -106,7 +106,7 @@ void up_sigdeliver(void)
    */
 
   sinfo("Resuming\n");
-  (void)up_irq_save();
+  up_irq_save();
   rtcb->pterrno = saved_errno;
 
   /* Modify the saved return state with the actual saved values in the

arch/arm/src/armv7-r/arm_signal_dispatch.c

@@ -93,8 +93,8 @@ void up_signal_dispatch(_sa_sigaction_t sighand, int signo,
     {
       /* Yes.. Let sys_call4() do all of the work to get us into user space */
 
-      (void)sys_call4(SYS_signal_handler, (uintptr_t)sighand, (uintptr_t)signo,
-                      (uintptr_t)info, (uintptr_t)ucontext);
+      sys_call4(SYS_signal_handler, (uintptr_t)sighand, (uintptr_t)signo,
+                (uintptr_t)info, (uintptr_t)ucontext);
     }
   else
     {

arch/arm/src/c5471/c5471_ethernet.c

@@ -989,8 +989,8 @@ static int c5471_transmit(struct c5471_driver_s *priv)
 
   /* Setup the TX timeout watchdog (perhaps restarting the timer) */
 
-  (void)wd_start(priv->c_txtimeout, C5471_TXTIMEOUT,
-                 c5471_txtimeout_expiry, 1, (wdparm_t)priv);
+  wd_start(priv->c_txtimeout, C5471_TXTIMEOUT,
+           c5471_txtimeout_expiry, 1, (wdparm_t)priv);
   return OK;
 }
 
@@ -1539,7 +1539,7 @@ static void c5471_txdone(struct c5471_driver_s *priv)
 
   /* Then poll the network for new XMIT data */
 
-  (void)devif_poll(&priv->c_dev, c5471_txpoll);
+  devif_poll(&priv->c_dev, c5471_txpoll);
 }
 
 /****************************************************************************
@@ -1707,7 +1707,7 @@ static void c5471_txtimeout_work(FAR void *arg)
 
   /* Then poll the network for new XMIT data */
 
-  (void)devif_poll(&priv->c_dev, c5471_txpoll);
+  devif_poll(&priv->c_dev, c5471_txpoll);
   net_unlock();
 }
 
@@ -1778,13 +1778,13 @@ static void c5471_poll_work(FAR void *arg)
     {
       /* If so, update TCP timing states and poll the network for new XMIT data */
 
-      (void)devif_timer(&priv->c_dev, C5471_WDDELAY, c5471_txpoll);
+      devif_timer(&priv->c_dev, C5471_WDDELAY, c5471_txpoll);
     }
 
   /* Setup the watchdog poll timer again */
 
-  (void)wd_start(priv->c_txpoll, C5471_WDDELAY, c5471_poll_expiry, 1,
-                 (wdparm_t)priv);
+  wd_start(priv->c_txpoll, C5471_WDDELAY, c5471_poll_expiry, 1,
+           (wdparm_t)priv);
   net_unlock();
 }
 
@@ -1870,8 +1870,8 @@ static int c5471_ifup(struct net_driver_s *dev)
 
   /* Set and activate a timer process */
 
-  (void)wd_start(priv->c_txpoll, C5471_WDDELAY, c5471_poll_expiry,
-                 1, (wdparm_t)priv);
+  wd_start(priv->c_txpoll, C5471_WDDELAY, c5471_poll_expiry,
+           1, (wdparm_t)priv);
 
   /* Enable the Ethernet interrupt */
 
@@ -1969,7 +1969,7 @@ static void c5471_txavail_work(FAR void *arg)
         {
           /* If so, then poll the network for new XMIT data */
 
-          (void)devif_poll(&priv->c_dev, c5471_txpoll);
+          devif_poll(&priv->c_dev, c5471_txpoll);
         }
     }
 
@@ -2458,7 +2458,7 @@ void up_netinitialize(void)
 
   /* Register the device with the OS so that socket IOCTLs can be performed */
 
-  (void)netdev_register(&g_c5471[0].c_dev, NET_LL_ETHERNET);
+  netdev_register(&g_c5471[0].c_dev, NET_LL_ETHERNET);
 }
 
 #endif /* CONFIG_NET */

arch/arm/src/c5471/c5471_serial.c

@@ -823,9 +823,9 @@ void up_earlyserialinit(void)
 
 void up_serialinit(void)
 {
-  (void)uart_register("/dev/console", &CONSOLE_DEV);
-  (void)uart_register("/dev/ttyS0", &TTYS0_DEV);
-  (void)uart_register("/dev/ttyS1", &TTYS1_DEV);
+  uart_register("/dev/console", &CONSOLE_DEV);
+  uart_register("/dev/ttyS0", &TTYS0_DEV);
+  uart_register("/dev/ttyS1", &TTYS1_DEV);
 }
 
 /****************************************************************************

arch/arm/src/common/up_exit.c

@@ -148,7 +148,7 @@ void _exit(int status)
    * The IRQ state will be restored when the next task is started.
    */
 
-  (void)enter_critical_section();
+  enter_critical_section();
 
   sinfo("TCB=%p exiting\n", tcb);
 
@@ -163,7 +163,7 @@ void _exit(int status)
 
   /* Destroy the task at the head of the ready to run list. */
 
-  (void)nxtask_exit();
+  nxtask_exit();
 
   /* Now, perform the context switch to the new ready-to-run task at the
    * head of the list.
@@ -178,7 +178,7 @@ void _exit(int status)
    * the ready-to-run list.
    */
 
-  (void)group_addrenv(tcb);
+  group_addrenv(tcb);
 #endif
 
   /* Reset scheduler parameters */

arch/arm/src/common/up_initialize.c

@@ -221,7 +221,7 @@ void up_initialize(void)
 #ifdef CONFIG_PSEUDOTERM_SUSV1
   /* Register the master pseudo-terminal multiplexor device */
 
-  (void)ptmx_register();
+  ptmx_register();
 #endif
 
   /* Early initialization of the system logging device.  Some SYSLOG channel
@@ -250,19 +250,19 @@ void up_initialize(void)
 #ifdef CONFIG_NETDEV_LOOPBACK
   /* Initialize the local loopback device */
 
-  (void)localhost_initialize();
+  localhost_initialize();
 #endif
 
 #ifdef CONFIG_NET_TUN
   /* Initialize the TUN device */
 
-  (void)tun_initialize();
+  tun_initialize();
 #endif
 
 #ifdef CONFIG_NETDEV_TELNET
   /* Initialize the Telnet session factory */
 
-  (void)telnet_initialize();
+  telnet_initialize();
 #endif
 
 #if defined(CONFIG_USBDEV) || defined(CONFIG_USBHOST)

arch/arm/src/common/up_lwl_console.c

@@ -323,5 +323,5 @@ static ssize_t lwlconsole_write(struct file *filep, const char *buffer,
 void lwlconsole_init(void)
 {
   g_d.upword = 0;
-  (void)register_driver("/dev/console", &g_consoleops, 0666, NULL);
+  register_driver("/dev/console", &g_consoleops, 0666, NULL);
 }

arch/arm/src/cxd56xx/cxd56_adc.c

@@ -585,7 +585,7 @@ static int adc_stop(adc_ch_t ch, FAR struct seq_s *seq)
       return OK;
     }
 
-  (void) seq_ioctl(seq, 0, SCUIOC_STOP, 0);
+  seq_ioctl(seq, 0, SCUIOC_STOP, 0);
 
   if (ch <= CH3)
     {
@@ -1006,11 +1006,7 @@ void cxd56_adc_getinterval(int adctype, uint32_t *interval, uint16_t *adjust)
 
 int cxd56_adcinitialize(void)
 {
-  int ret;
-
-  /* Avoid warnings when no ADC options enabled */
-
-  (void) ret;
+  int ret = OK;
 
 #if defined (CONFIG_CXD56_LPADC0) || defined (CONFIG_CXD56_LPADC0_1) || defined (CONFIG_CXD56_LPADC_ALL)
   ret = register_driver("/dev/lpadc0", &g_adcops, 0666, &g_lpadc0priv);
@@ -1061,5 +1057,5 @@ int cxd56_adcinitialize(void)
     }
 #endif
 
-  return OK;
+  return ret;
 }

arch/arm/src/cxd56xx/cxd56_charger.c

@@ -477,7 +477,7 @@ static int charger_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
   FAR struct charger_dev_s *priv  = inode->i_private;
   int ret = -ENOTTY;
 
-  sem_wait(&priv->batsem);
+  nxsem_wait(&priv->batsem);
 
   switch (cmd)
     {
@@ -621,7 +621,7 @@ static int charger_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
         break;
     }
 
-  sem_post(&priv->batsem);
+  nxsem_post(&priv->batsem);
 
   return ret;
 }
@@ -650,7 +650,7 @@ int cxd56_charger_initialize(FAR const char *devpath)
 
   /* Initialize the CXD5247 device structure */
 
-  sem_init(&priv->batsem, 0, 1);
+  nxsem_init(&priv->batsem, 0, 1);
 
   /* Register battery driver */
 
@@ -680,8 +680,7 @@ int cxd56_charger_initialize(FAR const char *devpath)
 
 int cxd56_charger_uninitialize(FAR const char *devpath)
 {
-  (void) unregister_driver(devpath);
-
+  unregister_driver(devpath);
   return OK;
 }
 

arch/arm/src/cxd56xx/cxd56_clock.c

@@ -235,7 +235,7 @@ static void clock_semtake(sem_t *id)
 {
   if (!up_interrupt_context())
     {
-      sem_wait(id);
+      nxsem_wait(id);
     }
 }
 
@@ -243,7 +243,7 @@ static void clock_semgive(sem_t *id)
 {
   if (!up_interrupt_context())
     {
-      sem_post(id);
+      nxsem_post(id);
     }
 }
 

arch/arm/src/cxd56xx/cxd56_cpuidlestack.c

@@ -98,7 +98,7 @@
 int up_cpu_idlestack(int cpu, FAR struct tcb_s *tcb, size_t stack_size)
 {
 #if CONFIG_SMP_NCPUS > 1
-  (void)up_create_stack(tcb, stack_size, TCB_FLAG_TTYPE_KERNEL);
+  up_create_stack(tcb, stack_size, TCB_FLAG_TTYPE_KERNEL);
 #endif
   return OK;
 }

arch/arm/src/cxd56xx/cxd56_cpustart.c

@@ -137,7 +137,7 @@ static void appdsp_boot(void)
 
   /* Then transfer control to the IDLE task */
 
-  (void)nx_idle_task(0, NULL);
+  nx_idle_task(0, NULL);
 }
 
 /****************************************************************************

arch/arm/src/cxd56xx/cxd56_dmac.c

@@ -677,7 +677,7 @@ void weak_function up_dma_initialize(void)
       g_dmach[i].chan = i;
     }
 
-  sem_init(&g_dmaexc, 0, 1);
+  nxsem_init(&g_dmaexc, 0, 1);
 }
 
 /****************************************************************************
@@ -711,7 +711,7 @@ DMA_HANDLE cxd56_dmachannel(int ch, ssize_t maxsize)
 
   /* Get exclusive access to allocate channel */
 
-  sem_wait(&g_dmaexc);
+  nxsem_wait(&g_dmaexc);
 
   if (ch < 0 || ch >= NCHANNELS)
     {
@@ -754,12 +754,12 @@ DMA_HANDLE cxd56_dmachannel(int ch, ssize_t maxsize)
 
   dmach->inuse  = true;
 
-  sem_post(&g_dmaexc);
+  nxsem_post(&g_dmaexc);
 
   return (DMA_HANDLE)dmach;
 
 err:
-  sem_post(&g_dmaexc);
+  nxsem_post(&g_dmaexc);
   return NULL;
 }
 
@@ -793,7 +793,7 @@ void cxd56_dmafree(DMA_HANDLE handle)
       return;
     }
 
-  sem_wait(&g_dmaexc);
+  nxsem_wait(&g_dmaexc);
 
   if (!dmach->inuse)
     {
@@ -811,7 +811,7 @@ void cxd56_dmafree(DMA_HANDLE handle)
   dmach->inuse = false;
 
 err:
-  sem_post(&g_dmaexc);
+  nxsem_post(&g_dmaexc);
 }
 
 /****************************************************************************

arch/arm/src/cxd56xx/cxd56_emmc.c

@@ -132,15 +132,12 @@ struct cxd56_emmc_state_s g_emmcdev;
 
 static void emmc_takesem(FAR sem_t *sem)
 {
-  while (sem_wait(sem) != 0)
-    {
-      ASSERT(errno == EINTR);
-    }
+  nxsem_wait_uninterruptible(sem);
 }
 
 static void emmc_givesem(FAR sem_t *sem)
 {
-  sem_post(sem);
+  nxsem_post(sem);
 }
 
 static void emmc_cmdstarted(void)
@@ -908,8 +905,8 @@ int cxd56_emmcinitialize(void)
   priv = &g_emmcdev;
 
   memset(priv, 0, sizeof(struct cxd56_emmc_state_s));
-  sem_init(&priv->excsem, 0, 1);
-  sem_init(&g_waitsem, 0, 0);
+  nxsem_init(&priv->excsem, 0, 1);
+  nxsem_init(&g_waitsem, 0, 0);
 
   ret = emmc_hwinitialize();
   if (ret != OK)