diff --git a/Documentation/reference/user/10_filesystem.rst b/Documentation/reference/user/10_filesystem.rst
index 4d162ae3e0..ce2a0c6044 100644
--- a/Documentation/reference/user/10_filesystem.rst
+++ b/Documentation/reference/user/10_filesystem.rst
@@ -396,8 +396,8 @@ Standard String Operations
   #include <strings.h>
 
   #define bcmp(b1,b2,len)  memcmp(b1,b2,(size_t)len)
-  #define bcopy(b1,b2,len) (void)memmove(b2,b1,len)
-  #define bzero(s,n)       (void)memset(s,0,n)
+  #define bcopy(b1,b2,len) memmove(b2,b1,len)
+  #define bzero(s,n)       memset(s,0,n)
   #define index(s,c)       strchr(s,c)
   #define rindex(s,c)      strrchr(s,c)
 
diff --git a/arch/arm/src/armv6-m/arm_svcall.c b/arch/arm/src/armv6-m/arm_svcall.c
index 1ccf869bc9..00b3ba486a 100644
--- a/arch/arm/src/armv6-m/arm_svcall.c
+++ b/arch/arm/src/armv6-m/arm_svcall.c
@@ -261,7 +261,7 @@ int arm_svcall(int irq, FAR void *context, FAR void *arg)
            */
 
           rtcb->flags          &= ~TCB_FLAG_SYSCALL;
-          (void)nxsig_unmask_pendingsignal();
+          nxsig_unmask_pendingsignal();
         }
         break;
 #endif
diff --git a/arch/arm/src/armv7-a/arm_syscall.c b/arch/arm/src/armv7-a/arm_syscall.c
index 80e06f55fc..9a55c08f92 100644
--- a/arch/arm/src/armv7-a/arm_syscall.c
+++ b/arch/arm/src/armv7-a/arm_syscall.c
@@ -239,7 +239,7 @@ uint32_t *arm_syscall(uint32_t *regs)
            */
 
           rtcb->flags          &= ~TCB_FLAG_SYSCALL;
-          (void)nxsig_unmask_pendingsignal();
+          nxsig_unmask_pendingsignal();
         }
         break;
 #endif
diff --git a/arch/arm/src/armv7-m/arm_svcall.c b/arch/arm/src/armv7-m/arm_svcall.c
index 71f526f010..1021d128e0 100644
--- a/arch/arm/src/armv7-m/arm_svcall.c
+++ b/arch/arm/src/armv7-m/arm_svcall.c
@@ -275,7 +275,7 @@ int arm_svcall(int irq, FAR void *context, FAR void *arg)
            */
 
           rtcb->flags          &= ~TCB_FLAG_SYSCALL;
-          (void)nxsig_unmask_pendingsignal();
+          nxsig_unmask_pendingsignal();
         }
         break;
 #endif
diff --git a/arch/arm/src/armv7-r/arm_syscall.c b/arch/arm/src/armv7-r/arm_syscall.c
index 4a576a4d01..ca42be8da9 100644
--- a/arch/arm/src/armv7-r/arm_syscall.c
+++ b/arch/arm/src/armv7-r/arm_syscall.c
@@ -236,7 +236,7 @@ uint32_t *arm_syscall(uint32_t *regs)
            */
 
           rtcb->flags          &= ~TCB_FLAG_SYSCALL;
-          (void)nxsig_unmask_pendingsignal();
+          nxsig_unmask_pendingsignal();
         }
         break;
 #endif
diff --git a/arch/arm/src/armv8-m/arm_svcall.c b/arch/arm/src/armv8-m/arm_svcall.c
index 351b1adcb7..74c40cd644 100644
--- a/arch/arm/src/armv8-m/arm_svcall.c
+++ b/arch/arm/src/armv8-m/arm_svcall.c
@@ -274,7 +274,7 @@ int arm_svcall(int irq, FAR void *context, FAR void *arg)
            */
 
           rtcb->flags          &= ~TCB_FLAG_SYSCALL;
-          (void)nxsig_unmask_pendingsignal();
+          nxsig_unmask_pendingsignal();
         }
         break;
 #endif
diff --git a/arch/arm/src/cxd56xx/cxd56_pwm.c b/arch/arm/src/cxd56xx/cxd56_pwm.c
index 3574089cfc..60dde8a18d 100644
--- a/arch/arm/src/cxd56xx/cxd56_pwm.c
+++ b/arch/arm/src/cxd56xx/cxd56_pwm.c
@@ -496,8 +496,6 @@ FAR struct pwm_lowerhalf_s *cxd56_pwminitialize(uint32_t channel)
 {
   FAR struct cxd56_pwm_chan_s *pwmch;
 
-  (void)g_pwmops;
-
   switch (channel)
     {
 #ifdef CONFIG_CXD56_PWM0
diff --git a/arch/arm/src/efm32/efm32_start.c b/arch/arm/src/efm32/efm32_start.c
index 77f71837d2..56af0be53a 100644
--- a/arch/arm/src/efm32/efm32_start.c
+++ b/arch/arm/src/efm32/efm32_start.c
@@ -84,7 +84,7 @@ const uintptr_t g_idle_topstack = HEAP_BASE;
 
 #ifdef CONFIG_DEBUG_FEATURES
 #  if defined(CONFIG_ARMV7M_ITMSYSLOG)
-#    define showprogress(c) (void)syslog_putc(c)
+#    define showprogress(c) syslog_putc(c)
 #  elif defined(HAVE_UART_CONSOLE) || defined(HAVE_LEUART_CONSOLE)
 #    define showprogress(c) efm32_lowputc(c)
 #  else
diff --git a/arch/arm/src/imxrt/imxrt_flexspi.c b/arch/arm/src/imxrt/imxrt_flexspi.c
index a36f84f455..10a4256a7a 100644
--- a/arch/arm/src/imxrt/imxrt_flexspi.c
+++ b/arch/arm/src/imxrt/imxrt_flexspi.c
@@ -581,7 +581,7 @@ void imxrt_flexspi_get_default_config(struct flexspi_config_s *config)
 {
   /* Initializes the configure structure to zero */
 
-  (void)memset(config, 0, sizeof(*config));
+  memset(config, 0, sizeof(*config));
 
   config->rx_sample_clock = FLEXSPI_READ_SAMPLE_CLK_LOOPBACK_FROM_DQS_PAD;
   config->enable_sck_free_running     = false;
@@ -606,8 +606,8 @@ void imxrt_flexspi_get_default_config(struct flexspi_config_s *config)
   config->ahb_config.ahb_grant_timeout_cycle  = 0xff;
   config->ahb_config.ahb_bus_timeout_cycle    = 0xffff;
   config->ahb_config.resume_wait_cycle        = 0x20;
-  (void)memset(config->ahb_config.buffer, 0,
-               sizeof(config->ahb_config.buffer));
+  memset(config->ahb_config.buffer, 0,
+         sizeof(config->ahb_config.buffer));
 
   /* Use invalid master ID 0xF and buffer size 0 for the first several
    * buffers.
diff --git a/arch/arm/src/imxrt/imxrt_usdhc.c b/arch/arm/src/imxrt/imxrt_usdhc.c
index c59dd9b0f1..466a731ab6 100644
--- a/arch/arm/src/imxrt/imxrt_usdhc.c
+++ b/arch/arm/src/imxrt/imxrt_usdhc.c
@@ -1330,8 +1330,8 @@ static int imxrt_interrupt(int irq, void *context, FAR void *arg)
           mcinfo("Queuing callback to %p(%p)\n",
                  priv->callback, priv->cbarg);
 
-          (void)work_queue(HPWORK, &priv->cbwork, priv->callback,
-                          priv->cbarg, 0);
+          work_queue(HPWORK, &priv->cbwork, priv->callback,
+                     priv->cbarg, 0);
         }
       else
         {
diff --git a/arch/arm/src/phy62xx/uart.c b/arch/arm/src/phy62xx/uart.c
index 7fb35383f4..07cdb44943 100644
--- a/arch/arm/src/phy62xx/uart.c
+++ b/arch/arm/src/phy62xx/uart.c
@@ -756,7 +756,7 @@ static int pplus_uart_interrupt(int irq, void *context, FAR void *arg)
           break;
 
       case BUSY_IRQ:
-         (void)priv->reg->USR;
+         priv->reg->USR;
          break;
 
       default:
@@ -1202,7 +1202,7 @@ static int h4uart_interrupt(int irq, void *context, FAR void *arg)
           break;
       case RLS_IRQ:
       case BUSY_IRQ:
-          (void)preg->USR;
+          preg->USR;
           break;
       default:
           break;
diff --git a/arch/arm/src/rtl8720c/ameba_uart.c b/arch/arm/src/rtl8720c/ameba_uart.c
index 377b60f3a1..77ccc5127c 100644
--- a/arch/arm/src/rtl8720c/ameba_uart.c
+++ b/arch/arm/src/rtl8720c/ameba_uart.c
@@ -1051,19 +1051,19 @@ void arm_earlyserialinit(void)
 void arm_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
 }
 
diff --git a/arch/arm/src/rtl8720c/ameba_wdt.c b/arch/arm/src/rtl8720c/ameba_wdt.c
index 969a7070b3..7fd08a0550 100644
--- a/arch/arm/src/rtl8720c/ameba_wdt.c
+++ b/arch/arm/src/rtl8720c/ameba_wdt.c
@@ -286,8 +286,8 @@ void ameba_wdt_initialize(void)
   /* Initialize the driver state structure. */
 
   priv->ops = &g_wdgops;
-  (void)watchdog_register(CONFIG_WATCHDOG_DEVPATH,
-                          (FAR struct watchdog_lowerhalf_s *)priv);
+  watchdog_register(CONFIG_WATCHDOG_DEVPATH,
+                    (FAR struct watchdog_lowerhalf_s *)priv);
 }
 
 #endif /* CONFIG_WATCHDOG */
diff --git a/arch/arm/src/rtl8720c/amebaz_coex.c b/arch/arm/src/rtl8720c/amebaz_coex.c
index 5ff7613e6d..a61c3391d3 100644
--- a/arch/arm/src/rtl8720c/amebaz_coex.c
+++ b/arch/arm/src/rtl8720c/amebaz_coex.c
@@ -86,12 +86,10 @@ static void rtk_notify_info_to_wifi(uint8_t length, uint8_t *report_info)
 }
 
 void bt_coex_handle_cmd_complete_evt(uint16_t opcode, uint16_t cause,
-                                              uint8_t total_len, uint8_t *p)
+                                     uint8_t total_len, uint8_t *p)
 {
-  (void)cause;
   if (opcode == HCI_VENDOR_MAILBOX_CMD)
     {
-      uint8_t status;
       status = *p++; /* jump the double subcmd */
 
       total_len--;
@@ -101,7 +99,6 @@ void bt_coex_handle_cmd_complete_evt(uint16_t opcode, uint16_t cause,
           return ;
         }
 
-      (void)status;
       rltk_coex_mailbox_to_wifi(p, total_len);
 
       /* rtk_parse_vendor_mailbox_cmd_evt(p, total_len, status); */
@@ -149,10 +146,10 @@ static void bt_coex_dump_buf(net_buf_simple *tmp_buf)
 
 static int bt_coex_unpack_xiaomi_vendor_cmd(net_buf_simple *tmp_buf)
 {
-  if (tmp_buf-> data[0] == 0x25 && tmp_buf-> data[1] == 0x00)
+  if (tmp_buf->data[0] == 0x25 && tmp_buf->data[1] == 0x00)
     {
-      tmp_buf -> data += 2;
-      tmp_buf -> len -= 2;
+      tmp_buf->data += 2;
+      tmp_buf->len -= 2;
       return 1;
     }
 
diff --git a/arch/arm/src/sam34/sam_gpioirq.c b/arch/arm/src/sam34/sam_gpioirq.c
index d32f145531..5f44da216b 100644
--- a/arch/arm/src/sam34/sam_gpioirq.c
+++ b/arch/arm/src/sam34/sam_gpioirq.c
@@ -433,7 +433,7 @@ void sam_gpioirqenable(int irq)
     {
       /* Clear (all) pending interrupts and enable this pin interrupt */
 
-      /* (void)getreg32(base + SAM_PIO_ISR_OFFSET); */
+      /* getreg32(base + SAM_PIO_ISR_OFFSET); */
 
       putreg32((1 << pin), base + SAM_PIO_IER_OFFSET);
     }
diff --git a/arch/arm/src/sama5/sam_pioirq.c b/arch/arm/src/sama5/sam_pioirq.c
index e87bb64584..9bc9b43dfd 100644
--- a/arch/arm/src/sama5/sam_pioirq.c
+++ b/arch/arm/src/sama5/sam_pioirq.c
@@ -479,7 +479,7 @@ void sam_pioirqenable(int irq)
     {
       /* Clear (all) pending interrupts and enable this pin interrupt */
 
-      (void)getreg32(base + SAM_PIO_ISR_OFFSET);
+      getreg32(base + SAM_PIO_ISR_OFFSET);
       putreg32((1 << pin), base + SAM_PIO_IER_OFFSET);
     }
 }
diff --git a/arch/arm/src/sama5/sam_sdmmc.c b/arch/arm/src/sama5/sam_sdmmc.c
index 1af67ac78d..241707dfb0 100644
--- a/arch/arm/src/sama5/sam_sdmmc.c
+++ b/arch/arm/src/sama5/sam_sdmmc.c
@@ -1427,8 +1427,8 @@ static int sam_interrupt(int irq, void *context, FAR void *arg)
 
           mcinfo("Queuing callback to %p(%p)\n", priv->callback,
                   priv->cbarg);
-          (void)work_queue(HPWORK, &priv->cbwork, priv->callback,
-                          priv->cbarg, 0);
+          work_queue(HPWORK, &priv->cbwork, priv->callback,
+                     priv->cbarg, 0);
         }
       else
         {
diff --git a/arch/arm/src/samd5e5/sam_oneshot.c b/arch/arm/src/samd5e5/sam_oneshot.c
index b5ebf70d82..769a5ea6f1 100644
--- a/arch/arm/src/samd5e5/sam_oneshot.c
+++ b/arch/arm/src/samd5e5/sam_oneshot.c
@@ -221,7 +221,7 @@ int sam_oneshot_start(struct sam_oneshot_s *oneshot,
       /* Yes.. then cancel it */
 
       tmrinfo("Already running... cancelling\n");
-      (void)sam_oneshot_cancel(oneshot, freerun, NULL);
+      sam_oneshot_cancel(oneshot, freerun, NULL);
     }
 
   /* Save the new handler and its argument */
diff --git a/arch/arm/src/samd5e5/sam_progmem.c b/arch/arm/src/samd5e5/sam_progmem.c
index e3f612d770..a5c3047b12 100644
--- a/arch/arm/src/samd5e5/sam_progmem.c
+++ b/arch/arm/src/samd5e5/sam_progmem.c
@@ -541,7 +541,7 @@ ssize_t up_progmem_eraseblock(size_t cluster)
   /* Erase all pages in the cluster */
 
 #ifdef USE_UNLOCK
-  (void)nvm_unlock(page, SAMD5E5_PAGE_PER_CLUSTER);
+  nvm_unlock(page, SAMD5E5_PAGE_PER_CLUSTER);
 #endif
 
   finfo("INFO: erase block=%d address=0x%x\n",
@@ -549,7 +549,7 @@ ssize_t up_progmem_eraseblock(size_t cluster)
   ret = nvm_command(NVMCTRL_CTRLB_CMD_EB, SAMD5E5_PAGE2BYTE(page));
 
 #ifdef USE_LOCK
-  (void)nvm_lock(page, SAMD5E5_PAGE_PER_CLUSTER);
+  nvm_lock(page, SAMD5E5_PAGE_PER_CLUSTER);
 #endif
 
   if (ret < 0)
@@ -698,7 +698,7 @@ ssize_t up_progmem_write(size_t address, const void *buffer, size_t buflen)
 #ifdef USE_UNLOCK /* Make sure that the FLASH is unlocked */
   lock = page;
   locksize = SAMD5E5_BYTE2PAGE(buflen);
-  (void)nvm_unlock(lock, locksize);
+  nvm_unlock(lock, locksize);
 #endif
 
   flags = enter_critical_section();
@@ -860,7 +860,7 @@ ssize_t up_progmem_write(size_t address, const void *buffer, size_t buflen)
     }
 
 #ifdef USE_LOCK
-  (void)nvm_lock(lock, locksize);
+  nvm_lock(lock, locksize);
 #endif
 
   leave_critical_section(flags);
diff --git a/arch/arm/src/samd5e5/sam_tc.c b/arch/arm/src/samd5e5/sam_tc.c
index 21073923d3..bcb81e1773 100644
--- a/arch/arm/src/samd5e5/sam_tc.c
+++ b/arch/arm/src/samd5e5/sam_tc.c
@@ -657,7 +657,7 @@ TC_HANDLE sam_tc_allocate(int tc, int frequency)
       /* Initialize the TC driver structure */
 
       priv->flags = 0;
-      (void)nxsem_init(&priv->exclsem, 0, 1);
+      nxsem_init(&priv->exclsem, 0, 1);
 
       /* Enable clocking to the TC module in PCHCTRL */
 
diff --git a/arch/arm/src/samd5e5/sam_timerisr.c b/arch/arm/src/samd5e5/sam_timerisr.c
index 2d51c5ead1..f540a6cf8a 100644
--- a/arch/arm/src/samd5e5/sam_timerisr.c
+++ b/arch/arm/src/samd5e5/sam_timerisr.c
@@ -113,7 +113,7 @@ void up_timer_initialize(void)
 
   /* Attach the timer interrupt vector */
 
-  (void)irq_attach(SAM_IRQ_SYSTICK, (xcpt_t)sam_timerisr, NULL);
+  irq_attach(SAM_IRQ_SYSTICK, (xcpt_t)sam_timerisr, NULL);
 
   /* Enable SysTick interrupts using the processor clock source. */
 
diff --git a/arch/arm/src/samd5e5/sam_wdt.c b/arch/arm/src/samd5e5/sam_wdt.c
index f337a2d2ec..cbbd79c32c 100644
--- a/arch/arm/src/samd5e5/sam_wdt.c
+++ b/arch/arm/src/samd5e5/sam_wdt.c
@@ -457,7 +457,7 @@ void sam_wdt_initialize(FAR const char *devpath)
   priv->started = false;
   sam_settimeout((FAR struct watchdog_lowerhalf_s *)priv,
                   BOARD_SCLK_FREQUENCY / 2);
-  (void)watchdog_register(devpath, (FAR struct watchdog_lowerhalf_s *)priv);
+  watchdog_register(devpath, (FAR struct watchdog_lowerhalf_s *)priv);
 }
 
 #endif /* CONFIG_WATCHDOG && CONFIG__WDT */
diff --git a/arch/arm/src/samv7/sam_gpioirq.c b/arch/arm/src/samv7/sam_gpioirq.c
index edbab38f3a..31d09a7d1a 100644
--- a/arch/arm/src/samv7/sam_gpioirq.c
+++ b/arch/arm/src/samv7/sam_gpioirq.c
@@ -389,7 +389,7 @@ void sam_gpioirqenable(int irq)
     {
       /* Clear (all) pending interrupts and enable this pin interrupt */
 
-      /* (void)getreg32(base + SAM_PIO_ISR_OFFSET); */
+      /* getreg32(base + SAM_PIO_ISR_OFFSET); */
 
       putreg32((1 << pin), base + SAM_PIO_IER_OFFSET);
     }
diff --git a/arch/arm/src/stm32h7/stm32_qspi.c b/arch/arm/src/stm32h7/stm32_qspi.c
index db08782c06..34f4a0a7dd 100644
--- a/arch/arm/src/stm32h7/stm32_qspi.c
+++ b/arch/arm/src/stm32h7/stm32_qspi.c
@@ -497,10 +497,11 @@ static inline void qspi_putreg(struct stm32h7_qspidev_s *priv,
 #ifdef CONFIG_DEBUG_SPI_INFO
 static void qspi_dumpregs(struct stm32h7_qspidev_s *priv, const char *msg)
 {
-  uint32_t regval;
   spiinfo("%s:\n", msg);
 
 #if 0
+  uint32_t regval;
+
   /* this extra verbose output may be helpful in some cases; you'll need
    * to make sure your syslog is large enough to accommodate extra output.
    */
@@ -575,7 +576,6 @@ static void qspi_dumpregs(struct stm32h7_qspidev_s *priv, const char *msg)
   spiinfo("   PIR:%08x  LPTR:%08x\n",
           getreg32(priv->base + STM32_QUADSPI_PIR_OFFSET),    /* Polling Interval Register */
           getreg32(priv->base + STM32_QUADSPI_LPTR_OFFSET));  /* Low-Power Timeout Register */
-  (void)regval;
 #endif
 }
 #endif
diff --git a/arch/arm/src/stm32h7/stm32_spi_slave.c b/arch/arm/src/stm32h7/stm32_spi_slave.c
index 1a5b3c3fe9..ff6a6e5d29 100644
--- a/arch/arm/src/stm32h7/stm32_spi_slave.c
+++ b/arch/arm/src/stm32h7/stm32_spi_slave.c
@@ -921,7 +921,7 @@ static int spi_lock(FAR struct spi_slave_ctrlr_s *ctrlr, bool lock)
     }
   else
     {
-      (void)nxsem_post(&priv->exclsem);
+      nxsem_post(&priv->exclsem);
       ret = OK;
     }
 
@@ -1156,8 +1156,8 @@ static void spi_bind(struct spi_slave_ctrlr_s *ctrlr,
 
   /* Bind to NSS interrupt */
 
-  (void)stm32_gpiosetevent(priv->nss_pin, false, true, false,
-                           spi_nssinterrupt, priv);
+  stm32_gpiosetevent(priv->nss_pin, false, true, false,
+                     spi_nssinterrupt, priv);
 
 #ifdef CONFIG_PM
   /* Register to receive power management callbacks */
@@ -1196,15 +1196,15 @@ static int spi_nssinterrupt(int irq, void *context, void *arg)
     {
       /* Bind to NSS rising edge interrupt */
 
-      (void)stm32_gpiosetevent(priv->nss_pin, true, false, false,
-                               spi_nssinterrupt, priv);
+      stm32_gpiosetevent(priv->nss_pin, true, false, false,
+                         spi_nssinterrupt, priv);
       return OK;
     }
 
   /* Disable NSS interrupt */
 
-  (void)stm32_gpiosetevent(priv->nss_pin, false, false, false,
-                           NULL, priv);
+  stm32_gpiosetevent(priv->nss_pin, false, false, false,
+                     NULL, priv);
 
   /* Re-configure nss pin */
 
diff --git a/arch/arm/src/stm32l5/stm32l5_irq.c b/arch/arm/src/stm32l5/stm32l5_irq.c
index ca543dad77..1398dea565 100644
--- a/arch/arm/src/stm32l5/stm32l5_irq.c
+++ b/arch/arm/src/stm32l5/stm32l5_irq.c
@@ -141,7 +141,7 @@ static void stm32l5_dumpnvic(const char *msg, int irq)
 #ifdef CONFIG_DEBUG_FEATURES
 static int stm32l5_nmi(int irq, FAR void *context, FAR void *arg)
 {
-  (void)up_irq_save();
+  up_irq_save();
   _err("PANIC!!! NMI received\n");
   PANIC();
   return 0;
@@ -149,7 +149,7 @@ static int stm32l5_nmi(int irq, FAR void *context, FAR void *arg)
 
 static int stm32l5_busfault(int irq, FAR void *context, FAR void *arg)
 {
-  (void)up_irq_save();
+  up_irq_save();
   _err("PANIC!!! Bus fault received: %08x\n", getreg32(NVIC_CFAULTS));
   PANIC();
   return 0;
@@ -157,7 +157,7 @@ static int stm32l5_busfault(int irq, FAR void *context, FAR void *arg)
 
 static int stm32l5_usagefault(int irq, FAR void *context, FAR void *arg)
 {
-  (void)up_irq_save();
+  up_irq_save();
   _err("PANIC!!! Usage fault received: %08x\n", getreg32(NVIC_CFAULTS));
   PANIC();
   return 0;
@@ -165,7 +165,7 @@ static int stm32l5_usagefault(int irq, FAR void *context, FAR void *arg)
 
 static int stm32l5_pendsv(int irq, FAR void *context, FAR void *arg)
 {
-  (void)up_irq_save();
+  up_irq_save();
   _err("PANIC!!! PendSV received\n");
   PANIC();
   return 0;
@@ -173,7 +173,7 @@ static int stm32l5_pendsv(int irq, FAR void *context, FAR void *arg)
 
 static int stm32l5_dbgmonitor(int irq, FAR void *context, FAR void *arg)
 {
-  (void)up_irq_save();
+  up_irq_save();
   _err("PANIC!!! Debug Monitor received\n");
   PANIC();
   return 0;
@@ -181,7 +181,7 @@ static int stm32l5_dbgmonitor(int irq, FAR void *context, FAR void *arg)
 
 static int stm32l5_reserved(int irq, FAR void *context, FAR void *arg)
 {
-  (void)up_irq_save();
+  up_irq_save();
   _err("PANIC!!! Reserved interrupt\n");
   PANIC();
   return 0;
diff --git a/arch/arm/src/stm32l5/stm32l5_lse.c b/arch/arm/src/stm32l5/stm32l5_lse.c
index ff754ba52e..3bc595b305 100644
--- a/arch/arm/src/stm32l5/stm32l5_lse.c
+++ b/arch/arm/src/stm32l5/stm32l5_lse.c
@@ -181,6 +181,6 @@ void stm32l5_rcc_enablelse(void)
 
       /* Disable backup domain access if it was disabled on entry */
 
-      (void)stm32l5_pwr_enablebkp(writable);
+      stm32l5_pwr_enablebkp(writable);
     }
 }
diff --git a/arch/arm/src/stm32l5/stm32l5_rcc.c b/arch/arm/src/stm32l5/stm32l5_rcc.c
index f214ba7770..86fb78a567 100644
--- a/arch/arm/src/stm32l5/stm32l5_rcc.c
+++ b/arch/arm/src/stm32l5/stm32l5_rcc.c
@@ -102,7 +102,7 @@ static inline void rcc_resetbkp(void)
        * backup data registers and backup SRAM).
        */
 
-      (void)stm32l5_pwr_enablebkp(true);
+      stm32l5_pwr_enablebkp(true);
 
       /* We might be changing RTCSEL - to ensure such changes work, we must
        * reset the backup domain (having backed up the RTC_MAGIC token)
@@ -123,7 +123,7 @@ static inline void rcc_resetbkp(void)
           putreg32(bkregs[i], STM32L5_RTC_BKR(i));
         }
 
-      (void)stm32l5_pwr_enablebkp(false);
+      stm32l5_pwr_enablebkp(false);
     }
 }
 #else
diff --git a/arch/arm/src/stm32l5/stm32l5_serial.c b/arch/arm/src/stm32l5/stm32l5_serial.c
index ecf4a3da96..50d667122b 100644
--- a/arch/arm/src/stm32l5/stm32l5_serial.c
+++ b/arch/arm/src/stm32l5/stm32l5_serial.c
@@ -1209,7 +1209,7 @@ static void stm32l5serial_setsuspend(struct uart_dev_s *dev, bool suspend)
 #ifdef CONFIG_SERIAL_IFLOWCONTROL
           if (priv->iflow)
             {
-              (void)stm32l5serial_dmaiflowrestart(priv);
+              stm32l5serial_dmaiflowrestart(priv);
             }
           else
 #endif
@@ -2644,7 +2644,7 @@ static void stm32l5serial_dmarxint(FAR struct uart_dev_s *dev, bool enable)
     {
       /* Re-enable RX DMA. */
 
-      (void)stm32l5serial_dmaiflowrestart(priv);
+      stm32l5serial_dmaiflowrestart(priv);
     }
 #endif
 }
@@ -2805,7 +2805,7 @@ static void stm32l5serial_dmarxcallback(DMA_HANDLE handle, uint8_t status,
         {
           /* Re-enable RX DMA. */
 
-          (void)stm32l5serial_dmaiflowrestart(priv);
+          stm32l5serial_dmaiflowrestart(priv);
         }
 #endif
     }
@@ -3076,14 +3076,14 @@ void arm_serialinit(void)
   /* Register the console */
 
 #if CONSOLE_UART > 0
-  (void)uart_register("/dev/console", &g_uart_devs[CONSOLE_UART - 1]->dev);
+  uart_register("/dev/console", &g_uart_devs[CONSOLE_UART - 1]->dev);
 
 #ifndef CONFIG_STM32L5_SERIAL_DISABLE_REORDERING
   /* If not disabled, register the console UART to ttyS0 and exclude
    * it from initializing it further down
    */
 
-  (void)uart_register("/dev/ttyS0", &g_uart_devs[CONSOLE_UART - 1]->dev);
+  uart_register("/dev/ttyS0", &g_uart_devs[CONSOLE_UART - 1]->dev);
   minor = 1;
 #endif
 
@@ -3119,7 +3119,7 @@ void arm_serialinit(void)
       /* Register USARTs as devices in increasing order */
 
       devname[9] = '0' + minor++;
-      (void)uart_register(devname, &g_uart_devs[i]->dev);
+      uart_register(devname, &g_uart_devs[i]->dev);
     }
 #endif /* HAVE UART */
 }
diff --git a/arch/arm/src/stm32l5/stm32l5_spi.c b/arch/arm/src/stm32l5/stm32l5_spi.c
index 3097820324..84fa3db5ad 100644
--- a/arch/arm/src/stm32l5/stm32l5_spi.c
+++ b/arch/arm/src/stm32l5/stm32l5_spi.c
@@ -689,7 +689,7 @@ static void spi_dmatxwait(FAR struct stm32l5_spidev_s *priv)
 #ifdef CONFIG_STM32L5_SPI_DMA
 static inline void spi_dmarxwakeup(FAR struct stm32l5_spidev_s *priv)
 {
-  (void)nxsem_post(&priv->rxsem);
+  nxsem_post(&priv->rxsem);
 }
 #endif
 
@@ -704,7 +704,7 @@ static inline void spi_dmarxwakeup(FAR struct stm32l5_spidev_s *priv)
 #ifdef CONFIG_STM32L5_SPI_DMA
 static inline void spi_dmatxwakeup(FAR struct stm32l5_spidev_s *priv)
 {
-  (void)nxsem_post(&priv->txsem);
+  nxsem_post(&priv->txsem);
 }
 #endif
 
@@ -953,7 +953,7 @@ static int spi_lock(FAR struct spi_dev_s *dev, bool lock)
     }
   else
     {
-      (void)nxsem_post(&priv->exclsem);
+      nxsem_post(&priv->exclsem);
       ret = OK;
     }
 
diff --git a/arch/arm/src/stm32l5/stm32l5_timerisr.c b/arch/arm/src/stm32l5/stm32l5_timerisr.c
index 28720a21d1..bd05e580b1 100644
--- a/arch/arm/src/stm32l5/stm32l5_timerisr.c
+++ b/arch/arm/src/stm32l5/stm32l5_timerisr.c
@@ -134,7 +134,7 @@ void up_timer_initialize(void)
 
   /* Attach the timer interrupt vector */
 
-  (void)irq_attach(STM32L5_IRQ_SYSTICK, (xcpt_t)stm32l5_timerisr, NULL);
+  irq_attach(STM32L5_IRQ_SYSTICK, (xcpt_t)stm32l5_timerisr, NULL);
 
   /* Enable SysTick interrupts */
 
diff --git a/arch/arm/src/stm32u5/stm32_irq.c b/arch/arm/src/stm32u5/stm32_irq.c
index 4d375b11d7..aa03270de3 100644
--- a/arch/arm/src/stm32u5/stm32_irq.c
+++ b/arch/arm/src/stm32u5/stm32_irq.c
@@ -141,7 +141,7 @@ static void stm32_dumpnvic(const char *msg, int irq)
 #ifdef CONFIG_DEBUG_FEATURES
 static int stm32_nmi(int irq, FAR void *context, FAR void *arg)
 {
-  (void)up_irq_save();
+  up_irq_save();
   _err("PANIC!!! NMI received\n");
   PANIC();
   return 0;
@@ -149,7 +149,7 @@ static int stm32_nmi(int irq, FAR void *context, FAR void *arg)
 
 static int stm32_busfault(int irq, FAR void *context, FAR void *arg)
 {
-  (void)up_irq_save();
+  up_irq_save();
   _err("PANIC!!! Bus fault received: %08x\n", getreg32(NVIC_CFAULTS));
   PANIC();
   return 0;
@@ -157,7 +157,7 @@ static int stm32_busfault(int irq, FAR void *context, FAR void *arg)
 
 static int stm32_usagefault(int irq, FAR void *context, FAR void *arg)
 {
-  (void)up_irq_save();
+  up_irq_save();
   _err("PANIC!!! Usage fault received: %08x\n", getreg32(NVIC_CFAULTS));
   PANIC();
   return 0;
@@ -165,7 +165,7 @@ static int stm32_usagefault(int irq, FAR void *context, FAR void *arg)
 
 static int stm32_pendsv(int irq, FAR void *context, FAR void *arg)
 {
-  (void)up_irq_save();
+  up_irq_save();
   _err("PANIC!!! PendSV received\n");
   PANIC();
   return 0;
@@ -173,7 +173,7 @@ static int stm32_pendsv(int irq, FAR void *context, FAR void *arg)
 
 static int stm32_dbgmonitor(int irq, FAR void *context, FAR void *arg)
 {
-  (void)up_irq_save();
+  up_irq_save();
   _err("PANIC!!! Debug Monitor received\n");
   PANIC();
   return 0;
@@ -181,7 +181,7 @@ static int stm32_dbgmonitor(int irq, FAR void *context, FAR void *arg)
 
 static int stm32_reserved(int irq, FAR void *context, FAR void *arg)
 {
-  (void)up_irq_save();
+  up_irq_save();
   _err("PANIC!!! Reserved interrupt\n");
   PANIC();
   return 0;
diff --git a/arch/arm/src/stm32u5/stm32_lse.c b/arch/arm/src/stm32u5/stm32_lse.c
index ed22eeae13..938bdaf85d 100644
--- a/arch/arm/src/stm32u5/stm32_lse.c
+++ b/arch/arm/src/stm32u5/stm32_lse.c
@@ -181,6 +181,6 @@ void stm32_rcc_enablelse(void)
 
       /* Disable backup domain access if it was disabled on entry */
 
-      (void)stm32_pwr_enablebkp(writable);
+      stm32_pwr_enablebkp(writable);
     }
 }
diff --git a/arch/arm/src/stm32u5/stm32_rcc.c b/arch/arm/src/stm32u5/stm32_rcc.c
index 18fb91b391..e7f2067ffe 100644
--- a/arch/arm/src/stm32u5/stm32_rcc.c
+++ b/arch/arm/src/stm32u5/stm32_rcc.c
@@ -102,7 +102,7 @@ static inline void rcc_resetbkp(void)
        * backup data registers and backup SRAM).
        */
 
-      (void)stm32_pwr_enablebkp(true);
+      stm32_pwr_enablebkp(true);
 
       /* We might be changing RTCSEL - to ensure such changes work, we must
        * reset the backup domain (having backed up the RTC_MAGIC token)
@@ -123,7 +123,7 @@ static inline void rcc_resetbkp(void)
           putreg32(bkregs[i], STM32U5_RTC_BKR(i));
         }
 
-      (void)stm32_pwr_enablebkp(false);
+      stm32_pwr_enablebkp(false);
     }
 }
 #else
diff --git a/arch/arm/src/stm32u5/stm32_serial.c b/arch/arm/src/stm32u5/stm32_serial.c
index a2e0ff3661..4bd823bda1 100644
--- a/arch/arm/src/stm32u5/stm32_serial.c
+++ b/arch/arm/src/stm32u5/stm32_serial.c
@@ -1209,7 +1209,7 @@ static void stm32serial_setsuspend(struct uart_dev_s *dev, bool suspend)
 #ifdef CONFIG_SERIAL_IFLOWCONTROL
           if (priv->iflow)
             {
-              (void)stm32serial_dmaiflowrestart(priv);
+              stm32serial_dmaiflowrestart(priv);
             }
           else
 #endif
@@ -2644,7 +2644,7 @@ static void stm32serial_dmarxint(FAR struct uart_dev_s *dev, bool enable)
     {
       /* Re-enable RX DMA. */
 
-      (void)stm32serial_dmaiflowrestart(priv);
+      stm32serial_dmaiflowrestart(priv);
     }
 #endif
 }
@@ -2804,7 +2804,7 @@ static void stm32serial_dmarxcallback(DMA_HANDLE handle, uint8_t status,
         {
           /* Re-enable RX DMA. */
 
-          (void)stm32serial_dmaiflowrestart(priv);
+          stm32serial_dmaiflowrestart(priv);
         }
 #endif
     }
@@ -3075,14 +3075,14 @@ void arm_serialinit(void)
   /* Register the console */
 
 #if CONSOLE_UART > 0
-  (void)uart_register("/dev/console", &g_uart_devs[CONSOLE_UART - 1]->dev);
+  uart_register("/dev/console", &g_uart_devs[CONSOLE_UART - 1]->dev);
 
 #ifndef CONFIG_STM32U5_SERIAL_DISABLE_REORDERING
   /* If not disabled, register the console UART to ttyS0 and exclude
    * it from initializing it further down
    */
 
-  (void)uart_register("/dev/ttyS0", &g_uart_devs[CONSOLE_UART - 1]->dev);
+  uart_register("/dev/ttyS0", &g_uart_devs[CONSOLE_UART - 1]->dev);
   minor = 1;
 #endif
 
@@ -3118,7 +3118,7 @@ void arm_serialinit(void)
       /* Register USARTs as devices in increasing order */
 
       devname[9] = '0' + minor++;
-      (void)uart_register(devname, &g_uart_devs[i]->dev);
+      uart_register(devname, &g_uart_devs[i]->dev);
     }
 #endif /* HAVE UART */
 }
diff --git a/arch/arm/src/stm32u5/stm32_timerisr.c b/arch/arm/src/stm32u5/stm32_timerisr.c
index 55585c6a1a..3722db7682 100644
--- a/arch/arm/src/stm32u5/stm32_timerisr.c
+++ b/arch/arm/src/stm32u5/stm32_timerisr.c
@@ -134,7 +134,7 @@ void up_timer_initialize(void)
 
   /* Attach the timer interrupt vector */
 
-  (void)irq_attach(STM32_IRQ_SYSTICK, (xcpt_t)stm32_timerisr, NULL);
+  irq_attach(STM32_IRQ_SYSTICK, (xcpt_t)stm32_timerisr, NULL);
 
   /* Enable SysTick interrupts */
 
diff --git a/arch/avr/src/at90usb/at90usb_serial.c b/arch/avr/src/at90usb/at90usb_serial.c
index 4f9cdc9cba..44b353297b 100644
--- a/arch/avr/src/at90usb/at90usb_serial.c
+++ b/arch/avr/src/at90usb/at90usb_serial.c
@@ -232,7 +232,7 @@ static int usart1_attach(struct uart_dev_s *dev)
   irq_attach(AT90USB_IRQ_U1RX, usart1_rxinterrupt, NULL);
   irq_attach(AT90USB_IRQ_U1DRE, usart1_txinterrupt, NULL);
 
-  /* (void)irq_attach(AT90USB_IRQ_U1TX, usart1_txinterrupt, NULL); */
+  /* irq_attach(AT90USB_IRQ_U1TX, usart1_txinterrupt, NULL); */
 
   return OK;
 }
@@ -258,7 +258,7 @@ static void usart1_detach(struct uart_dev_s *dev)
   irq_detach(AT90USB_IRQ_U1RX);
   irq_detach(AT90USB_IRQ_U1DRE);
 
-  /* (void)irq_detach(AT90USB_IRQ_U1TX); */
+  /* irq_detach(AT90USB_IRQ_U1TX); */
 }
 
 /****************************************************************************
diff --git a/arch/avr/src/atmega/atmega_serial.c b/arch/avr/src/atmega/atmega_serial.c
index 3f36b22076..94ff3dc955 100644
--- a/arch/avr/src/atmega/atmega_serial.c
+++ b/arch/avr/src/atmega/atmega_serial.c
@@ -371,7 +371,7 @@ static int usart0_attach(struct uart_dev_s *dev)
   irq_attach(ATMEGA_IRQ_U0RX, usart0_rxinterrupt, NULL);
   irq_attach(ATMEGA_IRQ_U0DRE, usart0_txinterrupt, NULL);
 
-  /* (void)irq_attach(ATMEGA_IRQ_U0TX, usart0_txinterrupt, NULL); */
+  /* irq_attach(ATMEGA_IRQ_U0TX, usart0_txinterrupt, NULL); */
 
   return OK;
 }
@@ -395,7 +395,7 @@ static int usart1_attach(struct uart_dev_s *dev)
   irq_attach(ATMEGA_IRQ_U1RX, usart1_rxinterrupt, NULL);
   irq_attach(ATMEGA_IRQ_U1DRE, usart1_txinterrupt, NULL);
 
-  /* (void)irq_attach(ATMEGA_IRQ_U1TX, usart1_txinterrupt, NULL); */
+  /* irq_attach(ATMEGA_IRQ_U1TX, usart1_txinterrupt, NULL); */
 
   return OK;
 }
@@ -423,7 +423,7 @@ static void usart0_detach(struct uart_dev_s *dev)
   irq_detach(ATMEGA_IRQ_U0RX);
   irq_detach(ATMEGA_IRQ_U0DRE);
 
-  /* (void)irq_detach(ATMEGA_IRQ_U0TX); */
+  /* irq_detach(ATMEGA_IRQ_U0TX); */
 }
 #endif
 
@@ -439,7 +439,7 @@ static void usart1_detach(struct uart_dev_s *dev)
   irq_detach(ATMEGA_IRQ_U1RX);
   irq_detach(ATMEGA_IRQ_U1DRE);
 
-  /* (void)irq_detach(ATMEGA_IRQ_U1TX); */
+  /* irq_detach(ATMEGA_IRQ_U1TX); */
 }
 #endif
 
diff --git a/arch/mips/include/syscall.h b/arch/mips/include/syscall.h
index 18039c7693..38022ece2a 100644
--- a/arch/mips/include/syscall.h
+++ b/arch/mips/include/syscall.h
@@ -163,7 +163,7 @@
  */
 
 #define SYS_syscall_return (3)
-#define up_syscall_return() (void)sys_call0(SYS_syscall_return)
+#define up_syscall_return() sys_call0(SYS_syscall_return)
 
 #endif
 #endif /* __ASSEMBLY__ */
diff --git a/arch/mips/src/mips32/mips_swint0.c b/arch/mips/src/mips32/mips_swint0.c
index 8fe8a5a1a2..191025bb62 100644
--- a/arch/mips/src/mips32/mips_swint0.c
+++ b/arch/mips/src/mips32/mips_swint0.c
@@ -230,7 +230,7 @@ int up_swint0(int irq, void *context, void *arg)
            */
 
           rtcb->flags            &= ~TCB_FLAG_SYSCALL;
-          (void)nxsig_unmask_pendingsignal();
+          nxsig_unmask_pendingsignal();
         }
         break;
 #endif
diff --git a/arch/misoc/include/syscall.h b/arch/misoc/include/syscall.h
index 8125775643..bbea8797cb 100644
--- a/arch/misoc/include/syscall.h
+++ b/arch/misoc/include/syscall.h
@@ -90,7 +90,7 @@
  */
 
 #define SYS_syscall_return (3)
-#define up_syscall_return() (void)sys_call0(SYS_syscall_return)
+#define up_syscall_return() sys_call0(SYS_syscall_return)
 
 #endif
 
diff --git a/arch/renesas/src/rx65n/rx65n_riic.c b/arch/renesas/src/rx65n/rx65n_riic.c
index 6baff6cb72..0336299316 100644
--- a/arch/renesas/src/rx65n/rx65n_riic.c
+++ b/arch/renesas/src/rx65n/rx65n_riic.c
@@ -2008,7 +2008,7 @@ static void rx65n_riic_pre_end_set(FAR struct rx65n_i2c_priv_s *priv)
       RIIC0.ICMR3.BIT.ACKBT = 1;
       RIIC0.ICMR3.BIT.ACKWP = 0;
 
-      (void)rx65n_getreg(RX65N_RIIC0_ICMR3);
+      rx65n_getreg(RX65N_RIIC0_ICMR3);
     }
 
   else if (1 == priv->bus)
@@ -2020,7 +2020,7 @@ static void rx65n_riic_pre_end_set(FAR struct rx65n_i2c_priv_s *priv)
       RIIC1.ICMR3.BIT.ACKBT = 1;
       RIIC1.ICMR3.BIT.ACKWP = 0;
 
-      (void)rx65n_getreg(RX65N_RIIC1_ICMR3);
+      rx65n_getreg(RX65N_RIIC1_ICMR3);
     }
 
   else
@@ -2032,7 +2032,7 @@ static void rx65n_riic_pre_end_set(FAR struct rx65n_i2c_priv_s *priv)
       RIIC2.ICMR3.BIT.ACKBT = 1;
       RIIC2.ICMR3.BIT.ACKWP = 0;
 
-      (void)rx65n_getreg(RX65N_RIIC2_ICMR3);
+      rx65n_getreg(RX65N_RIIC2_ICMR3);
     }
 }
 
diff --git a/arch/renesas/src/rx65n/rx65n_rtc.c b/arch/renesas/src/rx65n/rx65n_rtc.c
index 7f000609c6..2f7db40e07 100644
--- a/arch/renesas/src/rx65n/rx65n_rtc.c
+++ b/arch/renesas/src/rx65n/rx65n_rtc.c
@@ -553,7 +553,7 @@ int rx65n_rtc_setdatetime(FAR const struct tm *tp)
    * seconds)
    */
 
-  /* (void)gmtime_r(&tp->tv_sec, &tp); */
+  /* gmtime_r(&tp->tv_sec, &tp); */
 
   rtc_dumptime(&tp, "Setting time");
 
@@ -706,7 +706,7 @@ int up_rtc_settime(FAR const struct timespec *tp)
    * seconds)
    */
 
-  (void)gmtime_r(&tp->tv_sec, &newtime);
+  gmtime_r(&tp->tv_sec, &newtime);
   rtc_dumptime(&newtime, "Setting time");
 
   /* Then write the broken out values to the RTC */
diff --git a/arch/renesas/src/rx65n/rx65n_rtc_lowerhalf.c b/arch/renesas/src/rx65n/rx65n_rtc_lowerhalf.c
index cab2a382a7..3f3d44604a 100644
--- a/arch/renesas/src/rx65n/rx65n_rtc_lowerhalf.c
+++ b/arch/renesas/src/rx65n/rx65n_rtc_lowerhalf.c
@@ -467,7 +467,7 @@ static int rx65n_setrelative(FAR struct rtc_lowerhalf_s *lower,
 
           /* And convert the time back to broken out format */
 
-          (void)gmtime_r(&seconds, (FAR struct tm *)&setalarm.time);
+          gmtime_r(&seconds, (FAR struct tm *)&setalarm.time);
 
           /* The set the alarm using this absolute time */
 
diff --git a/arch/renesas/src/rx65n/rx65n_sbram.c b/arch/renesas/src/rx65n/rx65n_sbram.c
index abd91fb799..f47887ef99 100644
--- a/arch/renesas/src/rx65n/rx65n_sbram.c
+++ b/arch/renesas/src/rx65n/rx65n_sbram.c
@@ -278,7 +278,7 @@ static int rx65n_sbram_open(FAR struct file *filep)
 static int rx65n_sbram_internal_close(FAR struct sbramfh_s *bbf)
 {
   bbf->dirty = 0;
-  (void)clock_gettime(CLOCK_REALTIME, &bbf->lastwrite);
+  clock_gettime(CLOCK_REALTIME, &bbf->lastwrite);
   bbf->crc = rx65n_sbram_crc(bbf);
 
   SBRAM_DUMP(bbf, "close done");
diff --git a/arch/renesas/src/rx65n/rx65n_usbhost.c b/arch/renesas/src/rx65n/rx65n_usbhost.c
index a7976b9307..367a60c55d 100644
--- a/arch/renesas/src/rx65n/rx65n_usbhost.c
+++ b/arch/renesas/src/rx65n/rx65n_usbhost.c
@@ -3925,7 +3925,7 @@ static uint16_t usb_cstd_is_set_frdy (uint16_t pipe, uint16_t fifosel,
 
       buffer = hw_usb_read_syscfg();
       buffer = hw_usb_read_syssts();
-      (void)nxsig_usleep(1);
+      nxsig_usleep(1);
     }
 
   return (RX65N_USB_FIFO_ERROR);
@@ -6322,7 +6322,7 @@ static void rx65n_usbhost_bottomhalf (void *arg)
 
   else
     {
-      (void)nxsig_usleep(100);
+      nxsig_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",
@@ -6480,13 +6480,13 @@ static int rx65n_usbhost_rh_enumerate(struct usbhost_connection_s *conn,
 
   /* USB 2.0 spec says at least 50ms delay before port reset */
 
-  (void)nxsig_usleep(100 * 1000);
+  nxsig_usleep(100 * 1000);
 
   /* Put RH port 1 in reset.
    * Currently supporting only single downstream port)
    */
 
-  (void)nxsig_usleep(200 * 1000);
+  nxsig_usleep(200 * 1000);
   return OK;
 }
 
diff --git a/arch/risc-v/src/bl602/bl602_serial.c b/arch/risc-v/src/bl602/bl602_serial.c
index 9991492ee3..3b3ae9f42b 100644
--- a/arch/risc-v/src/bl602/bl602_serial.c
+++ b/arch/risc-v/src/bl602/bl602_serial.c
@@ -888,9 +888,6 @@ void riscv_serialinit(void)
 int up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
-  struct bl602_uart_s *priv = (struct bl602_uart_s *)CONSOLE_DEV.priv;
-  (void)priv;
-
   irqstate_t flags = enter_critical_section();
 
   /* Check for LF */
diff --git a/arch/risc-v/src/common/riscv_sigdeliver.c b/arch/risc-v/src/common/riscv_sigdeliver.c
index ac817be55a..ded797a405 100644
--- a/arch/risc-v/src/common/riscv_sigdeliver.c
+++ b/arch/risc-v/src/common/riscv_sigdeliver.c
@@ -120,7 +120,7 @@ void riscv_sigdeliver(void)
   DEBUGASSERT(rtcb->irqcount == 0);
   while (rtcb->irqcount < saved_irqcount)
     {
-      (void)enter_critical_section();
+      enter_critical_section();
     }
 #endif
 
diff --git a/arch/risc-v/src/common/riscv_swint.c b/arch/risc-v/src/common/riscv_swint.c
index 982d80addb..30f67a5438 100644
--- a/arch/risc-v/src/common/riscv_swint.c
+++ b/arch/risc-v/src/common/riscv_swint.c
@@ -297,7 +297,7 @@ int riscv_swint(int irq, void *context, void *arg)
            */
 
           rtcb->flags          &= ~TCB_FLAG_SYSCALL;
-          (void)nxsig_unmask_pendingsignal();
+          nxsig_unmask_pendingsignal();
         }
         break;
 #endif
diff --git a/arch/risc-v/src/rv32m1/rv32m1_irq.c b/arch/risc-v/src/rv32m1/rv32m1_irq.c
index cbe5c61534..094db7a2da 100644
--- a/arch/risc-v/src/rv32m1/rv32m1_irq.c
+++ b/arch/risc-v/src/rv32m1/rv32m1_irq.c
@@ -214,7 +214,7 @@ void up_enable_irq(int irq)
 
       /* Read INTPTEN back to make it sure */
 
-      (void)getreg32(RV32M1_EU_INTPTEN);
+      getreg32(RV32M1_EU_INTPTEN);
     }
 }
 
diff --git a/arch/sim/src/sim/up_macho_init.c b/arch/sim/src/sim/up_macho_init.c
index 27c85d8325..fe02e72dd2 100644
--- a/arch/sim/src/sim/up_macho_init.c
+++ b/arch/sim/src/sim/up_macho_init.c
@@ -67,7 +67,7 @@ allow_write(const void *start, const void *end)
    * the OS version.
    */
 
-  (void)mprotect(p, sz, PROT_READ | PROT_WRITE);
+  mprotect(p, sz, PROT_READ | PROT_WRITE);
 }
 
 __attribute__((constructor))
diff --git a/arch/sparc/include/syscall.h b/arch/sparc/include/syscall.h
index ade5ce1eb8..e82f78956f 100644
--- a/arch/sparc/include/syscall.h
+++ b/arch/sparc/include/syscall.h
@@ -70,7 +70,7 @@
 
 #define SYS_restore_context (1)
 #define up_fullcontextrestore(restoreregs) \
-  (void)sys_call1(SYS_restore_context, (uintptr_t)restoreregs)
+  sys_call1(SYS_restore_context, (uintptr_t)restoreregs)
 
 /* SYS call 2:
  *
@@ -79,7 +79,7 @@
 
 #define SYS_switch_context (2)
 #define up_switchcontext(saveregs, restoreregs) \
-  (void)sys_call2(SYS_switch_context, (uintptr_t)saveregs, (uintptr_t)restoreregs)
+  sys_call2(SYS_switch_context, (uintptr_t)saveregs, (uintptr_t)restoreregs)
 
 #ifdef CONFIG_BUILD_KERNEL
 /* SYS call 3:
@@ -88,7 +88,7 @@
  */
 
 #define SYS_syscall_return (3)
-#define up_syscall_return() (void)sys_call0(SYS_syscall_return)
+#define up_syscall_return() sys_call0(SYS_syscall_return)
 
 #endif
 #endif /* __ASSEMBLY__ */
diff --git a/arch/sparc/src/bm3803/bm3803-serial.c b/arch/sparc/src/bm3803/bm3803-serial.c
index c73bcb2679..b88d83cdd4 100644
--- a/arch/sparc/src/bm3803/bm3803-serial.c
+++ b/arch/sparc/src/bm3803/bm3803-serial.c
@@ -855,14 +855,14 @@ void up_serialinit(void)
   /* Register the console */
 
 #ifdef HAVE_SERIAL_CONSOLE
-  (void)uart_register("/dev/console", &CONSOLE_DEV);
+  uart_register("/dev/console", &CONSOLE_DEV);
 #endif
 
   /* Register all UARTs */
 
-  (void)uart_register("/dev/ttyS0", &TTYS0_DEV);
+  uart_register("/dev/ttyS0", &TTYS0_DEV);
 #ifdef TTYS1_DEV
-  (void)uart_register("/dev/ttyS1", &TTYS1_DEV);
+  uart_register("/dev/ttyS1", &TTYS1_DEV);
 #endif
 }
 
diff --git a/arch/sparc/src/bm3803/bm3803-timerisr.c b/arch/sparc/src/bm3803/bm3803-timerisr.c
index 1932c3caf3..fd0502a05f 100644
--- a/arch/sparc/src/bm3803/bm3803-timerisr.c
+++ b/arch/sparc/src/bm3803/bm3803-timerisr.c
@@ -123,12 +123,12 @@ void up_timer_initialize(void)
 
   up_clrpend_irq(BM3803_IRQ_TIMER1);
 #ifdef CONFIG_ARCH_IRQPRIO
-  (void)up_prioritize_irq(BM3803_IRQ_TIMER1, CONFIG_BM3803_TIMER1PRIO);
+  up_prioritize_irq(BM3803_IRQ_TIMER1, CONFIG_BM3803_TIMER1PRIO);
 #endif
 
   /* Attach the timer interrupt vector */
 
-  (void)irq_attach(BM3803_IRQ_TIMER1, (xcpt_t)bm3803_timerisr, NULL);
+  irq_attach(BM3803_IRQ_TIMER1, (xcpt_t)bm3803_timerisr, NULL);
 
   /* And enable the timer interrupt */
 
diff --git a/arch/sparc/src/bm3803/bm3803_oneshot.c b/arch/sparc/src/bm3803/bm3803_oneshot.c
index d45a4f6453..7a2c0e5ec5 100644
--- a/arch/sparc/src/bm3803/bm3803_oneshot.c
+++ b/arch/sparc/src/bm3803/bm3803_oneshot.c
@@ -217,7 +217,7 @@ int bm3803_oneshot_start(struct bm3803_oneshot_s *oneshot,
       /* Yes.. then cancel it */
 
       tmrinfo("Already running... cancelling\n");
-      (void)bm3803_oneshot_cancel(oneshot, NULL);
+      bm3803_oneshot_cancel(oneshot, NULL);
     }
 
   /* Save the new handler and its argument */
diff --git a/arch/sparc/src/bm3803/bm3803_wdg.c b/arch/sparc/src/bm3803/bm3803_wdg.c
index b8284751e5..603a5a714c 100644
--- a/arch/sparc/src/bm3803/bm3803_wdg.c
+++ b/arch/sparc/src/bm3803/bm3803_wdg.c
@@ -427,7 +427,7 @@ void bm3803_wdginitialize(const char *devpath)
 
   /* Register the watchdog driver as /dev/watchdog0 */
 
-  (void)watchdog_register(devpath, (struct watchdog_lowerhalf_s *)priv);
+  watchdog_register(devpath, (FAR struct watchdog_lowerhalf_s *)priv);
 }
 
 #endif /* CONFIG_WATCHDOG && CONFIG_BM3803_WDG */
diff --git a/arch/sparc/src/bm3823/bm3823-serial.c b/arch/sparc/src/bm3823/bm3823-serial.c
index 11f1f787c5..5c737a2c8f 100644
--- a/arch/sparc/src/bm3823/bm3823-serial.c
+++ b/arch/sparc/src/bm3823/bm3823-serial.c
@@ -847,14 +847,14 @@ void up_serialinit(void)
   /* Register the console */
 
 #ifdef HAVE_SERIAL_CONSOLE
-  (void)uart_register("/dev/console", &CONSOLE_DEV);
+  uart_register("/dev/console", &CONSOLE_DEV);
 #endif
 
   /* Register all UARTs */
 
-  (void)uart_register("/dev/ttyS0", &TTYS0_DEV);
+  uart_register("/dev/ttyS0", &TTYS0_DEV);
 #ifdef TTYS1_DEV
-  (void)uart_register("/dev/ttyS1", &TTYS1_DEV);
+  uart_register("/dev/ttyS1", &TTYS1_DEV);
 #endif
 }
 
diff --git a/arch/sparc/src/bm3823/bm3823-timerisr.c b/arch/sparc/src/bm3823/bm3823-timerisr.c
index b9500003cd..76fd5baae8 100644
--- a/arch/sparc/src/bm3823/bm3823-timerisr.c
+++ b/arch/sparc/src/bm3823/bm3823-timerisr.c
@@ -124,12 +124,12 @@ void up_timer_initialize(void)
 
   up_clrpend_irq(BM3823_IRQ_TIMER1);
 #ifdef CONFIG_ARCH_IRQPRIO
-  (void)up_prioritize_irq(BM3823_IRQ_TIMER1, CONFIG_BM3823_TIMER1PRIO);
+  up_prioritize_irq(BM3823_IRQ_TIMER1, CONFIG_BM3823_TIMER1PRIO);
 #endif
 
   /* Attach the timer interrupt vector */
 
-  (void)irq_attach(BM3823_IRQ_TIMER1, (xcpt_t)bm3823_timerisr, NULL);
+  irq_attach(BM3823_IRQ_TIMER1, (xcpt_t)bm3823_timerisr, NULL);
 
   /* And enable the timer interrupt */
 
diff --git a/arch/sparc/src/common/up_assert.c b/arch/sparc/src/common/up_assert.c
index 70b1c93562..9dde88df24 100644
--- a/arch/sparc/src/common/up_assert.c
+++ b/arch/sparc/src/common/up_assert.c
@@ -67,13 +67,13 @@ 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 (g_current_regs || running_task()->flink == NULL)
     {
-      (void)up_irq_save();
+      up_irq_save();
       for (; ; )
         {
 #if CONFIG_BOARD_RESET_ON_ASSERT >= 1
@@ -136,7 +136,7 @@ void up_assert(const char *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",
@@ -150,7 +150,7 @@ void up_assert(const char *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);
@@ -159,7 +159,7 @@ void up_assert(const char *filename, int lineno)
 #ifdef CONFIG_ARCH_USBDUMP
   /* Dump USB trace data */
 
-  (void)usbtrace_enumerate(assert_tracecallback, NULL);
+  usbtrace_enumerate(assert_tracecallback, NULL);
 #endif
 
   _up_assert(EXIT_FAILURE);
diff --git a/arch/sparc/src/sparc_v8/up_doirq.c b/arch/sparc/src/sparc_v8/up_doirq.c
index a6687b65b8..abfad3fd4a 100644
--- a/arch/sparc/src/sparc_v8/up_doirq.c
+++ b/arch/sparc/src/sparc_v8/up_doirq.c
@@ -98,7 +98,7 @@ uint32_t *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
diff --git a/arch/sparc/src/sparc_v8/up_sigdeliver.c b/arch/sparc/src/sparc_v8/up_sigdeliver.c
index ea33cedc9f..5e83b9c73f 100644
--- a/arch/sparc/src/sparc_v8/up_sigdeliver.c
+++ b/arch/sparc/src/sparc_v8/up_sigdeliver.c
@@ -91,7 +91,7 @@ void up_sigdeliver(void)
    */
 
   sinfo("Resuming\n");
-  (void)up_irq_save();
+  up_irq_save();
 
   /* Modify the saved return state with the actual saved values in the
    * TCB.  This depends on the fact that nested signal handling is
diff --git a/arch/x86_64/src/common/up_assert.c b/arch/x86_64/src/common/up_assert.c
index 02400a1e5c..93ec98c24f 100644
--- a/arch/x86_64/src/common/up_assert.c
+++ b/arch/x86_64/src/common/up_assert.c
@@ -200,7 +200,7 @@ 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
@@ -221,7 +221,7 @@ static void _up_assert(void)
 
   if (g_current_regs || (running_task())->flink == NULL)
     {
-      (void)up_irq_save();
+      up_irq_save();
       for (; ; )
         {
 #if CONFIG_BOARD_RESET_ON_ASSERT >= 1
diff --git a/arch/x86_64/src/common/up_blocktask.c b/arch/x86_64/src/common/up_blocktask.c
index b7ae8813f1..f87c5e9a46 100644
--- a/arch/x86_64/src/common/up_blocktask.c
+++ b/arch/x86_64/src/common/up_blocktask.c
@@ -147,7 +147,7 @@ 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 */
 
diff --git a/arch/x86_64/src/common/up_releasepending.c b/arch/x86_64/src/common/up_releasepending.c
index 1c5689d7f0..0eba1577a4 100644
--- a/arch/x86_64/src/common/up_releasepending.c
+++ b/arch/x86_64/src/common/up_releasepending.c
@@ -116,7 +116,7 @@ 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 */
 
diff --git a/arch/x86_64/src/common/up_reprioritizertr.c b/arch/x86_64/src/common/up_reprioritizertr.c
index c9461a187c..7b4f01da6a 100644
--- a/arch/x86_64/src/common/up_reprioritizertr.c
+++ b/arch/x86_64/src/common/up_reprioritizertr.c
@@ -170,7 +170,7 @@ 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 */
 
diff --git a/arch/x86_64/src/common/up_unblocktask.c b/arch/x86_64/src/common/up_unblocktask.c
index 519bdd7e48..cd3fff6db1 100644
--- a/arch/x86_64/src/common/up_unblocktask.c
+++ b/arch/x86_64/src/common/up_unblocktask.c
@@ -134,7 +134,7 @@ 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 */
 
diff --git a/arch/x86_64/src/intel64/intel64_handlers.c b/arch/x86_64/src/intel64/intel64_handlers.c
index b0b870a5c5..9367a705ce 100644
--- a/arch/x86_64/src/intel64/intel64_handlers.c
+++ b/arch/x86_64/src/intel64/intel64_handlers.c
@@ -99,7 +99,7 @@ static uint64_t *common_handler(int irq, uint64_t *regs)
        * thread at the head of the ready-to-run list.
        */
 
-      (void)group_addrenv(NULL);
+      group_addrenv(NULL);
 #endif
     }
 #endif
diff --git a/arch/x86_64/src/intel64/intel64_rng.c b/arch/x86_64/src/intel64/intel64_rng.c
index 0771be13a8..f3113098f4 100644
--- a/arch/x86_64/src/intel64/intel64_rng.c
+++ b/arch/x86_64/src/intel64/intel64_rng.c
@@ -173,7 +173,7 @@ static ssize_t x86_rngread(struct file *filep, char *buffer, size_t buflen)
 void devrandom_register(void)
 {
   x86_rng_initialize();
-  (void)register_driver("/dev/random", &g_rngops, 0444, NULL);
+  register_driver("/dev/random", &g_rngops, 0444, NULL);
 }
 #endif
 
@@ -197,7 +197,7 @@ void devurandom_register(void)
 #ifndef CONFIG_DEV_RANDOM
   x86_rng_initialize();
 #endif
-  (void)register_driver("/dev/urandom", &g_rngops, 0444, NULL);
+  register_driver("/dev/urandom", &g_rngops, 0444, NULL);
 }
 #endif
 
diff --git a/arch/x86_64/src/intel64/intel64_tickless.c b/arch/x86_64/src/intel64/intel64_tickless.c
index dcd51c50d9..573a93db33 100644
--- a/arch/x86_64/src/intel64/intel64_tickless.c
+++ b/arch/x86_64/src/intel64/intel64_tickless.c
@@ -129,9 +129,9 @@ void up_timer_initialize(void)
   g_last_stop_time = g_start_tsc = rdtsc();
 
 #ifndef CONFIG_SCHED_TICKLESS_ALARM
-  (void)irq_attach(TMR_IRQ, (xcpt_t)up_timer_expire, NULL);
+  irq_attach(TMR_IRQ, (xcpt_t)up_timer_expire, NULL);
 #else
-  (void)irq_attach(TMR_IRQ, (xcpt_t)up_alarm_expire, NULL);
+  irq_attach(TMR_IRQ, (xcpt_t)up_alarm_expire, NULL);
 #endif
 
   return;
diff --git a/arch/x86_64/src/intel64/intel64_timerisr.c b/arch/x86_64/src/intel64/intel64_timerisr.c
index ec6f4b4df8..bb9b0b642d 100644
--- a/arch/x86_64/src/intel64/intel64_timerisr.c
+++ b/arch/x86_64/src/intel64/intel64_timerisr.c
@@ -118,7 +118,7 @@ void up_timer_initialize(void)
   unsigned long ecx;
   uint32_t vector = IRQ0;
 
-  (void)irq_attach(IRQ0, (xcpt_t)intel64_timerisr, NULL);
+  irq_attach(IRQ0, (xcpt_t)intel64_timerisr, NULL);
 
 #ifdef CONFIG_ARCH_INTEL64_HAVE_TSC_DEADLINE
   vector |= MSR_X2APIC_LVTT_TSC_DEADLINE;
diff --git a/arch/x86_64/src/intel64/up_sigdeliver.c b/arch/x86_64/src/intel64/up_sigdeliver.c
index f489d361b3..dd79a48ed7 100644
--- a/arch/x86_64/src/intel64/up_sigdeliver.c
+++ b/arch/x86_64/src/intel64/up_sigdeliver.c
@@ -100,7 +100,7 @@ void up_sigdeliver(void)
    */
 
   sinfo("Resuming\n");
-  (void)up_irq_save();
+  up_irq_save();
 
   /* Modify the saved return state with the actual saved values in the
    * TCB.  This depends on the fact that nested signal handling is
diff --git a/boards/arm/nrf52/nrf52832-dk/src/nrf52_boot.c b/boards/arm/nrf52/nrf52832-dk/src/nrf52_boot.c
index 4472e2d2a2..a23cf76ca9 100644
--- a/boards/arm/nrf52/nrf52832-dk/src/nrf52_boot.c
+++ b/boards/arm/nrf52/nrf52832-dk/src/nrf52_boot.c
@@ -74,6 +74,6 @@ void board_late_initialize(void)
 {
   /* Perform board-specific initialization */
 
-  (void)nrf52_bringup();
+  nrf52_bringup();
 }
 #endif
diff --git a/boards/arm/nrf52/nrf52840-dk/src/nrf52_boot.c b/boards/arm/nrf52/nrf52840-dk/src/nrf52_boot.c
index 5afb11b033..5be5ac107f 100644
--- a/boards/arm/nrf52/nrf52840-dk/src/nrf52_boot.c
+++ b/boards/arm/nrf52/nrf52840-dk/src/nrf52_boot.c
@@ -80,6 +80,6 @@ void board_late_initialize(void)
 {
   /* Perform board-specific initialization */
 
-  (void)nrf52_bringup();
+  nrf52_bringup();
 }
 #endif
diff --git a/boards/arm/nrf52/nrf52840-dongle/src/nrf52_boot.c b/boards/arm/nrf52/nrf52840-dongle/src/nrf52_boot.c
index a0230a1bd7..46ccebde21 100644
--- a/boards/arm/nrf52/nrf52840-dongle/src/nrf52_boot.c
+++ b/boards/arm/nrf52/nrf52840-dongle/src/nrf52_boot.c
@@ -74,6 +74,6 @@ void board_late_initialize(void)
 {
   /* Perform board-specific initialization */
 
-  (void)nrf52_bringup();
+  nrf52_bringup();
 }
 #endif
diff --git a/boards/arm/samd2l2/arduino-m0/src/sam_boot.c b/boards/arm/samd2l2/arduino-m0/src/sam_boot.c
index b8b7739e52..9642ad7306 100644
--- a/boards/arm/samd2l2/arduino-m0/src/sam_boot.c
+++ b/boards/arm/samd2l2/arduino-m0/src/sam_boot.c
@@ -94,6 +94,6 @@ void board_late_initialize(void)
 {
   /* Perform board initialization */
 
-  (void)sam_bringup();
+  sam_bringup();
 }
 #endif /* CONFIG_BOARD_LATE_INITIALIZE */
diff --git a/boards/arm/samd2l2/circuit-express/src/sam_boot.c b/boards/arm/samd2l2/circuit-express/src/sam_boot.c
index e45589e432..2a5326e23c 100644
--- a/boards/arm/samd2l2/circuit-express/src/sam_boot.c
+++ b/boards/arm/samd2l2/circuit-express/src/sam_boot.c
@@ -81,6 +81,6 @@ void board_late_initialize(void)
 {
   /* Perform board initialization */
 
-  (void)sam_bringup();
+  sam_bringup();
 }
 #endif /* CONFIG_BOARD_LATE_INITIALIZE */
diff --git a/boards/arm/samd5e5/metro-m4/src/sam_automount.c b/boards/arm/samd5e5/metro-m4/src/sam_automount.c
index df7b3bb587..7b8b77446d 100644
--- a/boards/arm/samd5e5/metro-m4/src/sam_automount.c
+++ b/boards/arm/samd5e5/metro-m4/src/sam_automount.c
@@ -201,7 +201,7 @@ static void sam_enable(FAR const struct automount_lower_s *lower,
 
       if (state->handler)
         {
-          (void)state->handler(&config->lower, state->arg, true);
+          state->handler(&config->lower, state->arg, true);
         }
 
       state->pending = false;
@@ -320,7 +320,7 @@ void sam_automount_event(bool inserted)
         {
           /* No.. forward the event to the handler */
 
-          (void)state->handler(&config->lower, state->arg, state->inserted);
+          state->handler(&config->lower, state->arg, state->inserted);
         }
     }
 }
diff --git a/boards/arm/samd5e5/metro-m4/src/sam_bringup.c b/boards/arm/samd5e5/metro-m4/src/sam_bringup.c
index 6761d6c215..fd052b772e 100644
--- a/boards/arm/samd5e5/metro-m4/src/sam_bringup.c
+++ b/boards/arm/samd5e5/metro-m4/src/sam_bringup.c
@@ -95,7 +95,7 @@ int sam_bringup(void)
 #endif
 
 #if defined(CONFIG_SAMD5E5_WDT) && defined(CONFIG_WATCHDOG)
-  (void)sam_wdt_initialize(CONFIG_WATCHDOG_DEVPATH);
+  sam_wdt_initialize(CONFIG_WATCHDOG_DEVPATH);
 #endif
 
 #ifdef CONFIG_SAMD5E5_SERCOM5_ISI2C
diff --git a/boards/arm/samd5e5/metro-m4/src/sam_gpio.c b/boards/arm/samd5e5/metro-m4/src/sam_gpio.c
index c9a50d166d..1506bc9b05 100644
--- a/boards/arm/samd5e5/metro-m4/src/sam_gpio.c
+++ b/boards/arm/samd5e5/metro-m4/src/sam_gpio.c
@@ -287,7 +287,7 @@ int sam_gpio_initialize(void)
       g_gpin[i].gpio.gp_pintype = GPIO_INPUT_PIN;
       g_gpin[i].gpio.gp_ops     = &gpin_ops;
       g_gpin[i].id              = i;
-      (void)gpio_pin_register(&g_gpin[i].gpio, pincount);
+      gpio_pin_register(&g_gpin[i].gpio, pincount);
 
       /* Configure the pin that will be used as input */
 
@@ -305,7 +305,7 @@ int sam_gpio_initialize(void)
       g_gpout[i].gpio.gp_pintype = GPIO_OUTPUT_PIN;
       g_gpout[i].gpio.gp_ops     = &gpout_ops;
       g_gpout[i].id              = i;
-      (void)gpio_pin_register(&g_gpout[i].gpio, pincount);
+      gpio_pin_register(&g_gpout[i].gpio, pincount);
 
       /* Configure the pin that will be used as output */
 
@@ -322,7 +322,7 @@ int sam_gpio_initialize(void)
       g_gpint[i].samgpio.gpio.gp_pintype = GPIO_INTERRUPT_PIN;
       g_gpint[i].samgpio.gpio.gp_ops     = &gpint_ops;
       g_gpint[i].samgpio.id              = i;
-      (void)gpio_pin_register(&g_gpint[i].samgpio.gpio, pincount);
+      gpio_pin_register(&g_gpint[i].samgpio.gpio, pincount);
 
       /* Configure the pin that will be used as interrupt input */
 
diff --git a/boards/arm/samd5e5/same54-xplained-pro/src/sam_autoleds.c b/boards/arm/samd5e5/same54-xplained-pro/src/sam_autoleds.c
index 4822189a24..65a9e3b813 100644
--- a/boards/arm/samd5e5/same54-xplained-pro/src/sam_autoleds.c
+++ b/boards/arm/samd5e5/same54-xplained-pro/src/sam_autoleds.c
@@ -185,7 +185,7 @@ static int led_pm_prepare(struct pm_callback_s *cb, int domain,
 
 void board_autoled_initialize(void)
 {
-  (void)sam_portconfig(PORT_LED0);
+  sam_portconfig(PORT_LED0);
 }
 
 /****************************************************************************
diff --git a/boards/arm/samd5e5/same54-xplained-pro/src/sam_boot.c b/boards/arm/samd5e5/same54-xplained-pro/src/sam_boot.c
index 0c64bcb117..0d90ea80a5 100644
--- a/boards/arm/samd5e5/same54-xplained-pro/src/sam_boot.c
+++ b/boards/arm/samd5e5/same54-xplained-pro/src/sam_boot.c
@@ -74,6 +74,6 @@ void board_late_initialize(void)
 {
   /* Perform board-specific initialization */
 
-  (void)sam_bringup();
+  sam_bringup();
 }
 #endif
diff --git a/boards/arm/samv7/common/src/sam_automount.c b/boards/arm/samv7/common/src/sam_automount.c
index f00b6aa996..41199e1c67 100644
--- a/boards/arm/samv7/common/src/sam_automount.c
+++ b/boards/arm/samv7/common/src/sam_automount.c
@@ -190,7 +190,7 @@ static void sam_enable(FAR const struct automount_lower_s *lower,
       if (state->handler)
         {
           bool inserted = sam_cardinserted(config->hsmci);
-          (void)state->handler(&config->lower, state->arg, inserted);
+          state->handler(&config->lower, state->arg, inserted);
         }
 
       state->pending = false;
@@ -324,7 +324,7 @@ void sam_automount_event(int slotno, bool inserted)
         {
           /* No.. forward the event to the handler */
 
-          (void)state->handler(&config->lower, state->arg, inserted);
+          state->handler(&config->lower, state->arg, inserted);
         }
     }
 }
diff --git a/boards/arm/stm32/mikroe-stm32f4/src/stm32_vs1053.c b/boards/arm/stm32/mikroe-stm32f4/src/stm32_vs1053.c
index d20d5f3bed..e1fd639400 100644
--- a/boards/arm/stm32/mikroe-stm32f4/src/stm32_vs1053.c
+++ b/boards/arm/stm32/mikroe-stm32f4/src/stm32_vs1053.c
@@ -170,7 +170,7 @@ void up_vs1053initialize(FAR struct spi_dev_s * spi)
    *        until the RST line is asserted.
    */
 
-  /* (void)stm32_configgpio(GPIO_VS1053_RST); */
+  /* stm32_configgpio(GPIO_VS1053_RST); */
 
   /* Initialize the VS1053 DREQ GPIO line */
 
diff --git a/boards/arm/stm32/stm32butterfly2/src/stm32_butterfly2.h b/boards/arm/stm32/stm32butterfly2/src/stm32_butterfly2.h
index 0842271a16..a871027fdd 100644
--- a/boards/arm/stm32/stm32butterfly2/src/stm32_butterfly2.h
+++ b/boards/arm/stm32/stm32butterfly2/src/stm32_butterfly2.h
@@ -88,8 +88,6 @@ int stm32_mmcsd_initialize(int minor);
 #else
 static inline int stm32_mmcsd_initialize(int minor)
 {
-  (void)minor;
-
   return 0;
 }
 #endif
diff --git a/boards/arm/stm32/stm32f4discovery/src/stm32_cs43l22.c b/boards/arm/stm32/stm32f4discovery/src/stm32_cs43l22.c
index 0122f7e4a1..5f0fa4f799 100644
--- a/boards/arm/stm32/stm32f4discovery/src/stm32_cs43l22.c
+++ b/boards/arm/stm32/stm32f4discovery/src/stm32_cs43l22.c
@@ -277,7 +277,7 @@ int stm32_cs43l22_initialize(int minor)
 
       /* Configure the CS43L22 interrupt pin */
 
-      /* TODO: (void)stm32_configgpio(PIO_INT_CS43L22); */
+      /* TODO: stm32_configgpio(PIO_INT_CS43L22); */
 
       /* Get an instance of the I2C interface for the CS43L22 chip select */
 
diff --git a/boards/arm/stm32f7/stm32f746g-disco/src/stm32_sdmmc.c b/boards/arm/stm32f7/stm32f746g-disco/src/stm32_sdmmc.c
index cb44bae93f..39a282b0b9 100644
--- a/boards/arm/stm32f7/stm32f746g-disco/src/stm32_sdmmc.c
+++ b/boards/arm/stm32f7/stm32f746g-disco/src/stm32_sdmmc.c
@@ -113,8 +113,8 @@ int stm32_sdio_initialize(void)
 
   /* Register an interrupt handler for the card detect pin */
 
-  (void)stm32_gpiosetevent(GPIO_SDIO_NCD, true, true, true,
-                           stm32_ncd_interrupt, NULL);
+  stm32_gpiosetevent(GPIO_SDIO_NCD, true, true, true,
+                     stm32_ncd_interrupt, NULL);
 #endif
 
   /* Mount the SDIO-based MMC/SD block driver */
diff --git a/boards/arm/stm32h7/stm32h747i-disco/src/stm32_boot.c b/boards/arm/stm32h7/stm32h747i-disco/src/stm32_boot.c
index 596df355eb..fef6b5eed0 100644
--- a/boards/arm/stm32h7/stm32h747i-disco/src/stm32_boot.c
+++ b/boards/arm/stm32h7/stm32h747i-disco/src/stm32_boot.c
@@ -91,7 +91,7 @@ void board_late_initialize(void)
    * board_app_initialize().
    */
 
-  (void)stm32_bringup();
+  stm32_bringup();
 #endif
 }
 #endif
diff --git a/boards/arm/stm32l5/nucleo-l552ze/src/stm32_boot.c b/boards/arm/stm32l5/nucleo-l552ze/src/stm32_boot.c
index 5197c89083..4efde9a017 100644
--- a/boards/arm/stm32l5/nucleo-l552ze/src/stm32_boot.c
+++ b/boards/arm/stm32l5/nucleo-l552ze/src/stm32_boot.c
@@ -76,6 +76,6 @@ void board_late_initialize(void)
 {
   /* Perform board-specific initialization here if so configured */
 
-  (void)stm32_bringup();
+  stm32_bringup();
 }
 #endif
diff --git a/boards/arm/stm32l5/stm32l562e-dk/src/stm32_boot.c b/boards/arm/stm32l5/stm32l562e-dk/src/stm32_boot.c
index 14c71f414d..d9cf8c820e 100644
--- a/boards/arm/stm32l5/stm32l562e-dk/src/stm32_boot.c
+++ b/boards/arm/stm32l5/stm32l562e-dk/src/stm32_boot.c
@@ -85,6 +85,6 @@ void board_late_initialize(void)
 {
   /* Perform board-specific initialization here if so configured */
 
-  (void)stm32_bringup();
+  stm32_bringup();
 }
 #endif
diff --git a/boards/arm/stm32u5/b-u585i-iot02a/src/stm32_boot.c b/boards/arm/stm32u5/b-u585i-iot02a/src/stm32_boot.c
index 71b7e5a074..57655ee758 100644
--- a/boards/arm/stm32u5/b-u585i-iot02a/src/stm32_boot.c
+++ b/boards/arm/stm32u5/b-u585i-iot02a/src/stm32_boot.c
@@ -76,6 +76,6 @@ void board_late_initialize(void)
 {
   /* Perform board-specific initialization here if so configured */
 
-  (void)stm32_bringup();
+  stm32_bringup();
 }
 #endif
diff --git a/boards/renesas/rx65n/rx65n-grrose/src/rx65n_bringup.c b/boards/renesas/rx65n/rx65n-grrose/src/rx65n_bringup.c
index bc7262168a..88c7021203 100644
--- a/boards/renesas/rx65n/rx65n-grrose/src/rx65n_bringup.c
+++ b/boards/renesas/rx65n/rx65n-grrose/src/rx65n_bringup.c
@@ -382,13 +382,13 @@ int rx65n_bringup(void)
 #ifdef CONFIG_RX65N_SBRAM
   /* Initialize battery-backed RAM */
 
-  (void)rx65n_sbram_int();
+  rx65n_sbram_int();
 #endif
 
 #ifdef HAVE_DTC_DRIVER
   /* Initialize DTC */
 
-  (void)rx65n_dtc_initialize();
+  rx65n_dtc_initialize();
 #endif
 
 #if defined(CONFIG_USBHOST)
@@ -396,7 +396,7 @@ int rx65n_bringup(void)
 #endif
 
 #ifdef CONFIG_RX65N_RSPI
-  (void)rx65n_rspi_initialize();
+  rx65n_rspi_initialize();
 #endif
 
 #if defined(CONFIG_CDCACM) && !defined(CONFIG_CDCACM_CONSOLE)
diff --git a/boards/renesas/rx65n/rx65n-grrose/src/rx65n_sbram.c b/boards/renesas/rx65n/rx65n-grrose/src/rx65n_sbram.c
index a5c2382a48..158052ee44 100644
--- a/boards/renesas/rx65n/rx65n-grrose/src/rx65n_sbram.c
+++ b/boards/renesas/rx65n/rx65n-grrose/src/rx65n_sbram.c
@@ -242,7 +242,7 @@ static int hardfault_get_desc(struct sbramd_s *desc)
     {
       ret = file_ioctl(&filestruct, RX65N_SBRAM_GETDESC_IOCTL,
                        (unsigned long)((uintptr_t)desc));
-      (void)file_close(&filestruct);
+      file_close(&filestruct);
 
       if (ret < 0)
         {
@@ -340,7 +340,7 @@ void board_crashdump(uintptr_t currentsp, FAR void *tcb,
   FAR struct tcb_s *rtcb;
   int rv;
 
-  (void)enter_critical_section();
+  enter_critical_section();
 
   rtcb = (FAR struct tcb_s *)tcb;
 
diff --git a/boards/renesas/rx65n/rx65n-rsk2mb/src/rx65n_bringup.c b/boards/renesas/rx65n/rx65n-rsk2mb/src/rx65n_bringup.c
index cd43344b50..aaff33d9ad 100644
--- a/boards/renesas/rx65n/rx65n-rsk2mb/src/rx65n_bringup.c
+++ b/boards/renesas/rx65n/rx65n-rsk2mb/src/rx65n_bringup.c
@@ -377,17 +377,17 @@ int rx65n_bringup(void)
 #ifdef CONFIG_RX65N_SBRAM
   /* Initialize standby RAM */
 
-  (void)rx65n_sbram_int();
+  rx65n_sbram_int();
 #endif
 
 #ifdef HAVE_DTC_DRIVER
   /* Initialize DTC */
 
-  (void)rx65n_dtc_initialize();
+  rx65n_dtc_initialize();
 #endif
 
 #ifdef CONFIG_RX65N_RSPI
-  (void)rx65n_rspi_initialize();
+  rx65n_rspi_initialize();
 #endif
 
 #if defined(CONFIG_USBHOST)
diff --git a/boards/renesas/rx65n/rx65n-rsk2mb/src/rx65n_sbram.c b/boards/renesas/rx65n/rx65n-rsk2mb/src/rx65n_sbram.c
index 98bf5a5255..ab63ccfbf5 100644
--- a/boards/renesas/rx65n/rx65n-rsk2mb/src/rx65n_sbram.c
+++ b/boards/renesas/rx65n/rx65n-rsk2mb/src/rx65n_sbram.c
@@ -240,7 +240,7 @@ static int hardfault_get_desc(struct sbramd_s *desc)
     {
       ret = file_ioctl(&filestruct, RX65N_SBRAM_GETDESC_IOCTL,
                        (unsigned long)((uintptr_t)desc));
-      (void)file_close(&filestruct);
+      file_close(&filestruct);
 
       if (ret < 0)
         {
@@ -338,7 +338,7 @@ void board_crashdump(uintptr_t currentsp, FAR void *tcb,
   FAR struct tcb_s *rtcb;
   int rv;
 
-  (void)enter_critical_section();
+  enter_critical_section();
 
   rtcb = (FAR struct tcb_s *)tcb;
 
diff --git a/boards/sim/sim/sim/README.txt b/boards/sim/sim/sim/README.txt
index eebd532efb..ef5642f653 100644
--- a/boards/sim/sim/sim/README.txt
+++ b/boards/sim/sim/sim/README.txt
@@ -955,9 +955,9 @@ nxwm
         /* Execute the startup script */
 
       #ifdef CONFIG_NSH_ROMFSETC
-     -  (void)nsh_script(&pstate->cn_vtbl, "init", NSH_INITPATH);
+     -  nsh_script(&pstate->cn_vtbl, "init", NSH_INITPATH);
      +// REMOVE ME
-     +//  (void)nsh_script(&pstate->cn_vtbl, "init", NSH_INITPATH);
+     +//  nsh_script(&pstate->cn_vtbl, "init", NSH_INITPATH);
       #endif
 
         /* Then enter the command line parsing loop */
diff --git a/boards/sparc/bm3803/xx3803/src/bm3803_wdt.c b/boards/sparc/bm3803/xx3803/src/bm3803_wdt.c
index 1ccccfe6b3..b51d185f1e 100644
--- a/boards/sparc/bm3803/xx3803/src/bm3803_wdt.c
+++ b/boards/sparc/bm3803/xx3803/src/bm3803_wdt.c
@@ -132,7 +132,7 @@ int xx3803_watchdog_initialize(void)
 
   /*  Close watchdog as it is not needed here anymore */
 
-  (void)file_close(&filestruct);
+  file_close(&filestruct);
 
   if (ret < 0)
     {
diff --git a/drivers/audio/cxd56.c b/drivers/audio/cxd56.c
index 2bf83659d7..6ecbdbb0f1 100644
--- a/drivers/audio/cxd56.c
+++ b/drivers/audio/cxd56.c
@@ -3683,9 +3683,9 @@ static int cxd56_init_worker(FAR struct audio_lowerhalf_s *dev)
 
   pthread_attr_init(&t_attr);
   sparam.sched_priority = sched_get_priority_max(SCHED_FIFO) - 3;
-  (void)pthread_attr_setschedparam(&t_attr, &sparam);
-  (void)pthread_attr_setstacksize(&t_attr,
-                                  CONFIG_CXD56_AUDIO_WORKER_STACKSIZE);
+  pthread_attr_setschedparam(&t_attr, &sparam);
+  pthread_attr_setstacksize(&t_attr,
+                            CONFIG_CXD56_AUDIO_WORKER_STACKSIZE);
 
   ret = pthread_create(&priv->threadid, &t_attr, cxd56_workerthread,
                        (pthread_addr_t)priv);
diff --git a/drivers/audio/cxd56_src.c b/drivers/audio/cxd56_src.c
index 88b20315b7..5e9b84f299 100644
--- a/drivers/audio/cxd56_src.c
+++ b/drivers/audio/cxd56_src.c
@@ -462,9 +462,9 @@ int cxd56_src_init(FAR struct cxd56_dev_s *dev,
 
   pthread_attr_init(&t_attr);
   sparam.sched_priority = sched_get_priority_max(SCHED_FIFO) - 3;
-  (void)pthread_attr_setschedparam(&t_attr, &sparam);
-  (void)pthread_attr_setstacksize(&t_attr,
-                                  CONFIG_CXD56_AUDIO_SRC_STACKSIZE);
+  pthread_attr_setschedparam(&t_attr, &sparam);
+  pthread_attr_setstacksize(&t_attr,
+                            CONFIG_CXD56_AUDIO_SRC_STACKSIZE);
 
   ret = pthread_create(&g_src.threadid, &t_attr, cxd56_src_thread,
                        (pthread_addr_t)&g_src);
diff --git a/drivers/audio/wm8994.c b/drivers/audio/wm8994.c
index 75764fb7cf..ad756afebc 100644
--- a/drivers/audio/wm8994.c
+++ b/drivers/audio/wm8994.c
@@ -796,8 +796,8 @@ static int wm8994_start(FAR struct audio_lowerhalf_s *dev)
 
   pthread_attr_init(&tattr);
   sparam.sched_priority = sched_get_priority_max(SCHED_FIFO) - 3;
-  (void)pthread_attr_setschedparam(&tattr, &sparam);
-  (void)pthread_attr_setstacksize(&tattr, CONFIG_WM8994_WORKER_STACKSIZE);
+  pthread_attr_setschedparam(&tattr, &sparam);
+  pthread_attr_setstacksize(&tattr, CONFIG_WM8994_WORKER_STACKSIZE);
 
   audinfo("Starting worker thread\n");
   ret = pthread_create(&priv->threadid, &tattr, wm8994_workerthread,
@@ -837,9 +837,9 @@ static int wm8994_stop(FAR struct audio_lowerhalf_s *dev)
 
   term_msg.msg_id = AUDIO_MSG_STOP;
   term_msg.u.data = 0;
-  (void)file_mq_send(&priv->mq, (FAR const char *)&term_msg,
-                     sizeof(term_msg),
-                     CONFIG_WM8994_MSG_PRIO);
+  file_mq_send(&priv->mq, (FAR const char *)&term_msg,
+               sizeof(term_msg),
+               CONFIG_WM8994_MSG_PRIO);
 
   /* Join the worker thread */
 
diff --git a/drivers/serial/serial.c b/drivers/serial/serial.c
index de88768e2c..7b2c8b8622 100644
--- a/drivers/serial/serial.c
+++ b/drivers/serial/serial.c
@@ -163,7 +163,7 @@ static int uart_takesem(FAR sem_t *sem, bool errout)
  * Name: uart_givesem
  ****************************************************************************/
 
-#define uart_givesem(sem) (void)nxsem_post(sem)
+#define uart_givesem(sem) nxsem_post(sem)
 
 /****************************************************************************
  * Name: uart_pollnotify
diff --git a/drivers/usbhost/usbhost_cdcmbim.c b/drivers/usbhost/usbhost_cdcmbim.c
index d6c8df70ef..7429dda266 100644
--- a/drivers/usbhost/usbhost_cdcmbim.c
+++ b/drivers/usbhost/usbhost_cdcmbim.c
@@ -499,9 +499,9 @@ static ssize_t cdcwdm_read(FAR struct file *filep, FAR char *buffer,
       uinfo("Reading next message\n");
       if (work_available(&priv->comm_rxwork))
         {
-          (void)work_queue(LPWORK, &priv->comm_rxwork,
-                           usbhost_rxdata_work,
-                           priv, 0);
+          work_queue(LPWORK, &priv->comm_rxwork,
+                     (worker_t)usbhost_rxdata_work,
+                     priv, 0);
         }
     }
 
@@ -767,7 +767,7 @@ static void usbhost_freedevno(FAR struct usbhost_cdcmbim_s *priv)
 static inline void usbhost_mkdevname(FAR struct usbhost_cdcmbim_s *priv,
                                      FAR char *devname)
 {
-  (void)snprintf(devname, DEV_NAMELEN, DEV_FORMAT, priv->minor);
+  snprintf(devname, DEV_NAMELEN, DEV_FORMAT, priv->minor);
 }
 
 static void usbhost_bulkin_callback(FAR void *arg, ssize_t nbytes)
@@ -796,8 +796,8 @@ static void usbhost_bulkin_callback(FAR void *arg, ssize_t nbytes)
 
   if (work_available(&priv->bulk_rxwork))
     {
-      (void)work_queue(LPWORK, &priv->bulk_rxwork,
-                       usbhost_bulkin_work, priv, delay);
+      work_queue(LPWORK, &priv->bulk_rxwork,
+                 usbhost_bulkin_work, priv, delay);
     }
 }
 
@@ -1021,9 +1021,9 @@ static void usbhost_notification_work(FAR void *arg)
                 {
                   if (work_available(&priv->comm_rxwork))
                     {
-                      (void)work_queue(LPWORK, &priv->comm_rxwork,
-                                       usbhost_rxdata_work,
-                                       priv, 0);
+                      work_queue(LPWORK, &priv->comm_rxwork,
+                                 usbhost_rxdata_work,
+                                 priv, 0);
                     }
                 }
             }
@@ -1116,9 +1116,9 @@ static void usbhost_notification_callback(FAR void *arg, ssize_t nbytes)
 
       if (work_available(&priv->ntwork))
         {
-          (void)work_queue(LPWORK, &priv->ntwork,
-                           usbhost_notification_work,
-                           priv, delay);
+          work_queue(LPWORK, &priv->ntwork,
+                     usbhost_notification_work,
+                     priv, delay);
         }
     }
 }
@@ -1665,7 +1665,7 @@ static inline int usbhost_devinit(FAR struct usbhost_cdcmbim_s *priv)
 
   /* Register the network device */
 
-  (void)netdev_register(&priv->netdev, NET_LL_MBIM);
+  netdev_register(&priv->netdev, NET_LL_MBIM);
 
   /* Check if we successfully initialized. We now have to be concerned
    * about asynchronous modification of crefs because the character
@@ -2128,7 +2128,7 @@ static int usbhost_disconnected(struct usbhost_class_s *usbclass)
           uinfo("Queuing destruction: worker %p->%p\n",
                 priv->destroywork.worker, usbhost_destroy);
           DEBUGASSERT(priv->destroywork.worker == NULL);
-          (void)work_queue(LPWORK, &priv->destroywork,
+          work_queue(LPWORK, &priv->destroywork,
                            usbhost_destroy, priv, 0);
         }
       else
@@ -2316,7 +2316,7 @@ static void cdcmbim_txpoll_work(void *arg)
   net_lock();
   priv->netdev.d_buf = priv->txpktbuf;
 
-  (void)devif_timer(&priv->netdev, CDCMBIM_WDDELAY, cdcmbim_txpoll);
+  devif_timer(&priv->netdev, CDCMBIM_WDDELAY, cdcmbim_txpoll);
 
   /* setup the watchdog poll timer again */
 
@@ -2496,7 +2496,7 @@ static void cdcmbim_txavail_work(void *arg)
 
   if (priv->bifup)
     {
-      (void)devif_timer(&priv->netdev, 0, cdcmbim_txpoll);
+      devif_timer(&priv->netdev, 0, cdcmbim_txpoll);
     }
 
   net_unlock();
diff --git a/fs/unionfs/fs_unionfs.c b/fs/unionfs/fs_unionfs.c
index 36dfcf3030..7c7ea37f54 100644
--- a/fs/unionfs/fs_unionfs.c
+++ b/fs/unionfs/fs_unionfs.c
@@ -96,7 +96,7 @@ struct unionfs_file_s
 /* Helper functions */
 
 static int     unionfs_semtake(FAR struct unionfs_inode_s *ui, bool noint);
-#define        unionfs_semgive(ui) (void)nxsem_post(&(ui)->ui_exclsem)
+#define        unionfs_semgive(ui) nxsem_post(&(ui)->ui_exclsem)
 
 static FAR const char *unionfs_offsetpath(FAR const char *relpath,
                  FAR const char *prefix);
diff --git a/include/strings.h b/include/strings.h
index f0c216db32..9b763ccc2e 100644
--- a/include/strings.h
+++ b/include/strings.h
@@ -46,11 +46,11 @@
 #endif
 
 #ifndef bcopy /* See mm/README.txt */
-#define bcopy(b1,b2,len) (void)memmove(b2,b1,len)
+#define bcopy(b1,b2,len) memmove(b2,b1,len)
 #endif
 
 #ifndef bzero /* See mm/README.txt */
-#define bzero(s,n)       (void)memset(s,0,n)
+#define bzero(s,n)       memset(s,0,n)
 #endif
 
 #define strcasecmp_l(s1, s2, l)     strcasecmp(s1, s2)
diff --git a/libs/libc/stream/lib_memoutstream.c b/libs/libc/stream/lib_memoutstream.c
index 91ca00f588..58c673e312 100644
--- a/libs/libc/stream/lib_memoutstream.c
+++ b/libs/libc/stream/lib_memoutstream.c
@@ -67,7 +67,7 @@ static int memoutstream_puts(FAR struct lib_outstream_s *this,
 static void memoutstream_putc(FAR struct lib_outstream_s *this, int ch)
 {
   char tmp = ch;
-  (void)memoutstream_puts(this, &tmp, 1);
+  memoutstream_puts(this, &tmp, 1);
 }
 
 /****************************************************************************
diff --git a/libs/libc/stream/lib_rawsostream.c b/libs/libc/stream/lib_rawsostream.c
index 48342462ec..0c417cd64c 100644
--- a/libs/libc/stream/lib_rawsostream.c
+++ b/libs/libc/stream/lib_rawsostream.c
@@ -76,7 +76,7 @@ static int rawoutstream_puts(FAR struct lib_outstream_s *this,
 static void rawoutstream_putc(FAR struct lib_outstream_s *this, int ch)
 {
   char tmp = ch;
-  (void)rawoutstream_puts(this, &tmp, 1);
+  rawoutstream_puts(this, &tmp, 1);
 }
 
 /****************************************************************************
diff --git a/net/route/net_cacheroute.c b/net/route/net_cacheroute.c
index c6629b75ac..5f6dd12ce7 100644
--- a/net/route/net_cacheroute.c
+++ b/net/route/net_cacheroute.c
@@ -180,8 +180,8 @@ static sem_t g_ipv6_cachelock = SEM_INITIALIZER(1);
  *
  ****************************************************************************/
 
-#define net_unlock_ipv4_cache() (void)nxsem_post(&g_ipv4_cachelock)
-#define net_unlock_ipv6_cache() (void)nxsem_post(&g_ipv6_cachelock)
+#define net_unlock_ipv4_cache() nxsem_post(&g_ipv4_cachelock)
+#define net_unlock_ipv6_cache() nxsem_post(&g_ipv6_cachelock)
 
 /****************************************************************************
  * Name: net_add_newest_ipv4 and net_add_newest_ipv6
diff --git a/tools/incdir.c b/tools/incdir.c
index 8b108dd1e2..585aa25599 100644
--- a/tools/incdir.c
+++ b/tools/incdir.c
@@ -389,8 +389,8 @@ int main(int argc, char **argv, char **envp)
               exit(EXIT_FAILURE);
             }
 
-          (void)cygwin_conv_path(CCP_POSIX_TO_WIN_A, dirname, convpath,
-                                 bufsize);
+          cygwin_conv_path(CCP_POSIX_TO_WIN_A, dirname, convpath,
+                           bufsize);
           incpath = convpath;
         }
       else
diff --git a/tools/mksyscall.c b/tools/mksyscall.c
index 352bd1c4b7..a03c8080ef 100644
--- a/tools/mksyscall.c
+++ b/tools/mksyscall.c
@@ -313,7 +313,7 @@ static void generate_proxy(int nfixed, int nparms)
   if (strcmp(g_parm[RETTYPE_INDEX], "void") == 0 ||
       strcmp(g_parm[RETTYPE_INDEX], "noreturn") == 0)
     {
-      fprintf(stream, "  (void)sys_call%d(", nparms);
+      fprintf(stream, "  sys_call%d(", nparms);
     }
   else
     {