diff --git a/Documentation/reference/os/arch.rst b/Documentation/reference/os/arch.rst
index 1fd49f1fc4..8afe4bcb48 100644
--- a/Documentation/reference/os/arch.rst
+++ b/Documentation/reference/os/arch.rst
@@ -288,7 +288,7 @@ APIs Exported by Architecture-Specific Logic to NuttX
   architectures, it should be avoided in common implementations
   where possible.
 
-.. c:function::  int up_putc(int ch)
+.. c:function::  void up_putc(int ch)
 
   This is a debug interface exported by the
   architecture-specific logic. Output one character on the console
diff --git a/arch/arm/src/a1x/a1x_serial.c b/arch/arm/src/a1x/a1x_serial.c
index bd7faf265d..7ffd1820c4 100644
--- a/arch/arm/src/a1x/a1x_serial.c
+++ b/arch/arm/src/a1x/a1x_serial.c
@@ -1566,7 +1566,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -1578,8 +1578,6 @@ int up_putc(int ch)
 #ifdef HAVE_SERIAL_CONSOLE
   up_restoreuartint(priv, ier);
 #endif
-
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -1592,12 +1590,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART_DEVICE
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/am335x/am335x_serial.c b/arch/arm/src/am335x/am335x_serial.c
index f937709820..8ec878fb01 100644
--- a/arch/arm/src/am335x/am335x_serial.c
+++ b/arch/arm/src/am335x/am335x_serial.c
@@ -1370,7 +1370,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -1382,8 +1382,6 @@ int up_putc(int ch)
 #ifdef HAVE_SERIAL_CONSOLE
   up_restoreuartint(priv, ier);
 #endif
-
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -1396,12 +1394,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART_DEVICE
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/at32/at32_serial.c b/arch/arm/src/at32/at32_serial.c
index e2018e48cd..c73457d085 100644
--- a/arch/arm/src/at32/at32_serial.c
+++ b/arch/arm/src/at32/at32_serial.c
@@ -2997,7 +2997,7 @@ void at32_serial_dma_poll(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_UART > 0
   struct up_dev_s *priv = g_uart_devs[CONSOLE_UART - 1];
@@ -3007,7 +3007,6 @@ int up_putc(int ch)
   arm_lowputc(ch);
   up_restoreusartint(priv, ie);
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -3020,12 +3019,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_UART > 0
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/c5471/c5471_serial.c b/arch/arm/src/c5471/c5471_serial.c
index 0165210284..788bbebd8a 100644
--- a/arch/arm/src/c5471/c5471_serial.c
+++ b/arch/arm/src/c5471/c5471_serial.c
@@ -830,7 +830,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
   uint16_t  ier;
@@ -841,5 +841,4 @@ int up_putc(int ch)
 
   up_waittxready(priv);
   up_restoreuartint(priv, ier);
-  return ch;
 }
diff --git a/arch/arm/src/common/arm_semi_syslog.c b/arch/arm/src/common/arm_semi_syslog.c
index 43562db01d..530b346861 100644
--- a/arch/arm/src/common/arm_semi_syslog.c
+++ b/arch/arm/src/common/arm_semi_syslog.c
@@ -45,10 +45,9 @@
  * Name: up_putc
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   smh_call(SEMI_SYSLOG_WRITEC, &ch);
-  return ch;
 }
 
 /****************************************************************************
diff --git a/arch/arm/src/cxd32xx/cxd32_serial.c b/arch/arm/src/cxd32xx/cxd32_serial.c
index 384a9d26de..5642b0cb78 100644
--- a/arch/arm/src/cxd32xx/cxd32_serial.c
+++ b/arch/arm/src/cxd32xx/cxd32_serial.c
@@ -970,7 +970,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_CONSOLE
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -982,8 +982,6 @@ int up_putc(int ch)
 #ifdef HAVE_CONSOLE
   up_restoreuartint(priv, ier);
 #endif
-
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/cxd56xx/cxd56_serial.c b/arch/arm/src/cxd56xx/cxd56_serial.c
index f73f054c49..eadb023808 100644
--- a/arch/arm/src/cxd56xx/cxd56_serial.c
+++ b/arch/arm/src/cxd56xx/cxd56_serial.c
@@ -1108,7 +1108,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_CONSOLE
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -1120,8 +1120,6 @@ int up_putc(int ch)
 #ifdef HAVE_CONSOLE
   up_restoreuartint(priv, ier);
 #endif
-
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -1134,12 +1132,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/dm320/dm320_serial.c b/arch/arm/src/dm320/dm320_serial.c
index 2bc8dbdb77..8f150dfb30 100644
--- a/arch/arm/src/dm320/dm320_serial.c
+++ b/arch/arm/src/dm320/dm320_serial.c
@@ -742,7 +742,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
   uint16_t  ier;
@@ -753,7 +753,6 @@ int up_putc(int ch)
 
   up_waittxready(priv);
   up_restoreuartint(priv, ier);
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -789,13 +788,12 @@ static inline void up_waittxready(void)
  * Public Functions
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   up_waittxready();
   putreg16((uint16_t)ch, DM320_REGISTER_BASE + UART_DTRR);
 
   up_waittxready();
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/efm32/efm32_leserial.c b/arch/arm/src/efm32/efm32_leserial.c
index 4af6c30373..fe80a0410a 100644
--- a/arch/arm/src/efm32/efm32_leserial.c
+++ b/arch/arm/src/efm32/efm32_leserial.c
@@ -809,7 +809,7 @@ void arm_serialinit(void)
  ****************************************************************************/
 
 #ifdef HAVE_LEUART_CONSOLE
-int up_putc(int ch)
+void up_putc(int ch)
 {
   struct efm32_leuart_s *priv = (struct efm32_leuart_s *)CONSOLE_DEV.priv;
   uint32_t ien;
@@ -817,7 +817,6 @@ int up_putc(int ch)
   efm32_disableuartint(priv, &ien);
   efm32_lowputc(ch);
   efm32_restoreuartint(priv, ien);
-  return ch;
 }
 #endif
 
@@ -832,10 +831,9 @@ int up_putc(int ch)
  ****************************************************************************/
 
 #ifdef HAVE_LEUART_CONSOLE
-int up_putc(int ch)
+void up_putc(int ch)
 {
   efm32_lowputc(ch);
-  return ch;
 }
 #endif
 
diff --git a/arch/arm/src/efm32/efm32_serial.c b/arch/arm/src/efm32/efm32_serial.c
index 7dc45cec1f..522add0825 100644
--- a/arch/arm/src/efm32/efm32_serial.c
+++ b/arch/arm/src/efm32/efm32_serial.c
@@ -1185,7 +1185,7 @@ void arm_serialinit(void)
  ****************************************************************************/
 
 #ifndef HAVE_LEUART_CONSOLE
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART_CONSOLE
   struct efm32_usart_s *priv = (struct efm32_usart_s *)CONSOLE_DEV.priv;
@@ -1195,7 +1195,6 @@ int up_putc(int ch)
   efm32_lowputc(ch);
   efm32_restoreuartint(priv, ien);
 #endif
-  return ch;
 }
 #endif
 
@@ -1210,12 +1209,11 @@ int up_putc(int ch)
  ****************************************************************************/
 
 #ifndef HAVE_LEUART_CONSOLE
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART_CONSOLE
   efm32_lowputc(ch);
 #endif
-  return ch;
 }
 #endif
 
diff --git a/arch/arm/src/eoss3/eoss3_serial.c b/arch/arm/src/eoss3/eoss3_serial.c
index e4ab6393d0..20a277b096 100644
--- a/arch/arm/src/eoss3/eoss3_serial.c
+++ b/arch/arm/src/eoss3/eoss3_serial.c
@@ -581,7 +581,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef CONFIG_UART_SERIAL_CONSOLE
   struct eoss3_uart_s *priv = (struct eoss3_uart_s *)g_uartport.priv;
@@ -591,8 +591,6 @@ int up_putc(int ch)
   arm_lowputc(ch);
   eoss3_restoreuartint(priv, ie);
 #endif
-
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -605,12 +603,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   /* Output the character */
 
   arm_lowputc(ch);
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/fvp-v8r-aarch32/fvp_serial.c b/arch/arm/src/fvp-v8r-aarch32/fvp_serial.c
index 677f9ae2bc..12ed7f4d99 100644
--- a/arch/arm/src/fvp-v8r-aarch32/fvp_serial.c
+++ b/arch/arm/src/fvp-v8r-aarch32/fvp_serial.c
@@ -78,9 +78,8 @@ void arm_serialinit(void)
 
 #else /* USE_SERIALDRIVER */
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
-  return 0;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/gd32f4/gd32f4xx_serial.c b/arch/arm/src/gd32f4/gd32f4xx_serial.c
index 334fefe889..9d131c0b10 100644
--- a/arch/arm/src/gd32f4/gd32f4xx_serial.c
+++ b/arch/arm/src/gd32f4/gd32f4xx_serial.c
@@ -2929,7 +2929,7 @@ void gd32_serial_dma_poll(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef CONSOLE_UART
 
@@ -2940,7 +2940,6 @@ int up_putc(int ch)
   arm_lowputc(ch);
   up_restoreusartint(priv, ie);
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -2953,12 +2952,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef CONSOLE_UART
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/imx1/imx_serial.c b/arch/arm/src/imx1/imx_serial.c
index 701d231ae0..e87f87660a 100644
--- a/arch/arm/src/imx1/imx_serial.c
+++ b/arch/arm/src/imx1/imx_serial.c
@@ -1158,7 +1158,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
   uint32_t ier;
@@ -1169,7 +1169,6 @@ int up_putc(int ch)
   up_serialout(priv, UART_TXD0, (uint32_t)ch);
   up_waittxready(priv);
   up_restoreuartint(priv, ier);
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -1211,11 +1210,10 @@ static inline void up_waittxready(void)
  * Public Functions
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   up_waittxready();
   putreg32((uint16_t)ch, IMX_REGISTER_BASE + UART_TXD0);
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/imx6/imx_serial.c b/arch/arm/src/imx6/imx_serial.c
index cfca29fe07..903b802bfa 100644
--- a/arch/arm/src/imx6/imx_serial.c
+++ b/arch/arm/src/imx6/imx_serial.c
@@ -1114,7 +1114,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   struct imx_uart_s *priv = (struct imx_uart_s *)CONSOLE_DEV.priv;
   uint32_t ier;
@@ -1126,8 +1126,6 @@ int up_putc(int ch)
   imx_disableuartint(priv, &ier);
   imx_lowputc(ch);
   imx_restoreuartint(priv, ier);
-
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -1176,14 +1174,12 @@ static inline void imx_waittxready(void)
  * Public Functions
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef IMX_CONSOLE_VBASE
   imx_waittxready();
   putreg32((uint16_t)ch, IMX_CONSOLE_VBASE + UART_TXD_OFFSET);
 #endif
-
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/imxrt/imxrt_serial.c b/arch/arm/src/imxrt/imxrt_serial.c
index d87790f68b..c0f19f2f54 100644
--- a/arch/arm/src/imxrt/imxrt_serial.c
+++ b/arch/arm/src/imxrt/imxrt_serial.c
@@ -3671,7 +3671,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef CONSOLE_DEV
   struct imxrt_uart_s *priv = (struct imxrt_uart_s *)CONSOLE_DEV.dev.priv;
@@ -3681,8 +3681,6 @@ int up_putc(int ch)
   imxrt_lowputc(ch);
   imxrt_restoreuartint(priv, ie);
 #endif
-
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -3695,13 +3693,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_LPUART > 0
   arm_lowputc(ch);
 #endif
-
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/kinetis/kinetis_lpserial.c b/arch/arm/src/kinetis/kinetis_lpserial.c
index a4cf3a3545..1893851bef 100644
--- a/arch/arm/src/kinetis/kinetis_lpserial.c
+++ b/arch/arm/src/kinetis/kinetis_lpserial.c
@@ -1949,7 +1949,7 @@ void kinetis_lpserial_dma_poll(void)
  ****************************************************************************/
 
 #ifdef HAVE_LPUART_PUTC
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_LPUART_CONSOLE
   struct kinetis_dev_s *priv = (struct kinetis_dev_s *)CONSOLE_DEV.priv;
@@ -1959,7 +1959,6 @@ int up_putc(int ch)
   arm_lowputc(ch);
   kinetis_restoreuartint(priv, ie);
 #endif
-  return ch;
 }
 #endif
 
@@ -1974,12 +1973,11 @@ int up_putc(int ch)
  ****************************************************************************/
 
 #ifdef HAVE_LPUART_PUTC
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_LPUART_CONSOLE
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 #endif
 
diff --git a/arch/arm/src/kinetis/kinetis_serial.c b/arch/arm/src/kinetis/kinetis_serial.c
index d7a3edd242..38fdb6337f 100644
--- a/arch/arm/src/kinetis/kinetis_serial.c
+++ b/arch/arm/src/kinetis/kinetis_serial.c
@@ -2141,7 +2141,7 @@ void kinetis_serial_dma_poll(void)
  ****************************************************************************/
 
 #ifdef HAVE_UART_PUTC
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART_CONSOLE
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -2151,7 +2151,6 @@ int up_putc(int ch)
   arm_lowputc(ch);
   up_restoreuartint(priv, ie);
 #endif
-  return ch;
 }
 #endif
 
@@ -2166,12 +2165,11 @@ int up_putc(int ch)
  ****************************************************************************/
 
 #ifdef HAVE_UART_PUTC
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART_CONSOLE
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 #endif
 
diff --git a/arch/arm/src/kl/kl_serial.c b/arch/arm/src/kl/kl_serial.c
index 9afe34d9bf..e9f759b09e 100644
--- a/arch/arm/src/kl/kl_serial.c
+++ b/arch/arm/src/kl/kl_serial.c
@@ -875,7 +875,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -885,7 +885,6 @@ int up_putc(int ch)
   kl_lowputc(ch);
   up_restoreuartint(priv, ie);
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -898,12 +897,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   kl_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/lc823450/lc823450_serial.c b/arch/arm/src/lc823450/lc823450_serial.c
index a767768f5c..54fe1bc934 100644
--- a/arch/arm/src/lc823450/lc823450_serial.c
+++ b/arch/arm/src/lc823450/lc823450_serial.c
@@ -1358,7 +1358,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
   uint32_t im;
@@ -1366,7 +1366,7 @@ int up_putc(int ch)
 #ifdef CONFIG_DEV_CONSOLE_SWITCH
   if (g_console_disable)
     {
-      return ch;
+      return;
     }
 #endif /* CONFIG_DEV_CONSOLE_SWITCH */
 
@@ -1376,7 +1376,6 @@ int up_putc(int ch)
 
   up_waittxnotfull(priv);
   up_restoreuartint(priv, im);
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -1389,10 +1388,9 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   arm_lowputc(ch);
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/lpc17xx_40xx/lpc17_40_serial.c b/arch/arm/src/lpc17xx_40xx/lpc17_40_serial.c
index 3216721f22..1397e4b382 100644
--- a/arch/arm/src/lpc17xx_40xx/lpc17_40_serial.c
+++ b/arch/arm/src/lpc17xx_40xx/lpc17_40_serial.c
@@ -1684,7 +1684,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_CONSOLE
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -1696,8 +1696,6 @@ int up_putc(int ch)
 #ifdef HAVE_CONSOLE
   up_restoreuartint(priv, ier);
 #endif
-
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -1710,12 +1708,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/lpc214x/lpc214x_serial.c b/arch/arm/src/lpc214x/lpc214x_serial.c
index 22807163df..1b64a1370b 100644
--- a/arch/arm/src/lpc214x/lpc214x_serial.c
+++ b/arch/arm/src/lpc214x/lpc214x_serial.c
@@ -783,7 +783,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
   uint8_t ier;
@@ -794,7 +794,6 @@ int up_putc(int ch)
 
   up_waittxready(priv);
   up_restoreuartint(priv, ier);
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -807,10 +806,9 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   arm_lowputc(ch);
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/lpc2378/lpc23xx_serial.c b/arch/arm/src/lpc2378/lpc23xx_serial.c
index 66fcd842b6..c49cc1b1fb 100644
--- a/arch/arm/src/lpc2378/lpc23xx_serial.c
+++ b/arch/arm/src/lpc2378/lpc23xx_serial.c
@@ -923,7 +923,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
   uint8_t ier;
@@ -934,7 +934,6 @@ int up_putc(int ch)
 
   up_waittxready(priv);
   up_restoreuartint(priv, ier);
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -947,9 +946,8 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   arm_lowputc(ch);
-  return ch;
 }
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/lpc31xx/lpc31_serial.c b/arch/arm/src/lpc31xx/lpc31_serial.c
index 9ffc996ca3..6477abc3bc 100644
--- a/arch/arm/src/lpc31xx/lpc31_serial.c
+++ b/arch/arm/src/lpc31xx/lpc31_serial.c
@@ -797,7 +797,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   struct up_dev_s *priv = &g_uartpriv;
   uint8_t ier;
@@ -812,7 +812,6 @@ int up_putc(int ch)
 
   arm_lowputc(ch);
   up_restoreuartint(priv, ier);
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -825,12 +824,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   /* Output the character */
 
   arm_lowputc(ch);
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/lpc43xx/lpc43_serial.c b/arch/arm/src/lpc43xx/lpc43_serial.c
index e53b924784..279cddafe0 100644
--- a/arch/arm/src/lpc43xx/lpc43_serial.c
+++ b/arch/arm/src/lpc43xx/lpc43_serial.c
@@ -1348,7 +1348,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -1360,8 +1360,6 @@ int up_putc(int ch)
 #ifdef HAVE_SERIAL_CONSOLE
   up_restoreuartint(priv, ier);
 #endif
-
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -1374,12 +1372,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/lpc54xx/lpc54_serial.c b/arch/arm/src/lpc54xx/lpc54_serial.c
index 81d6fe8ed8..c17a2e4ee7 100644
--- a/arch/arm/src/lpc54xx/lpc54_serial.c
+++ b/arch/arm/src/lpc54xx/lpc54_serial.c
@@ -1440,7 +1440,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_USART_CONSOLE
   struct lpc54_dev_s *priv = (struct lpc54_dev_s *)CONSOLE_DEV.priv;
@@ -1450,8 +1450,6 @@ int up_putc(int ch)
   arm_lowputc(ch);
   lpc54_fifoint_enable(priv, intset);
 #endif
-
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -1464,11 +1462,10 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_USART_CONSOLE
   arm_lowputc(ch);
-  return ch;
 }
 #endif
 
diff --git a/arch/arm/src/max326xx/max32660/max32660_serial.c b/arch/arm/src/max326xx/max32660/max32660_serial.c
index 43573db43f..e4e1265e25 100644
--- a/arch/arm/src/max326xx/max32660/max32660_serial.c
+++ b/arch/arm/src/max326xx/max32660/max32660_serial.c
@@ -825,7 +825,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART_CONSOLE
   struct max326_dev_s *priv = (struct max326_dev_s *)CONSOLE_DEV.priv;
@@ -835,8 +835,6 @@ int up_putc(int ch)
   arm_lowputc(ch);
   max326_int_enable(priv, intset);
 #endif
-
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -849,11 +847,10 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART_CONSOLE
   arm_lowputc(ch);
-  return ch;
 }
 #endif
 
diff --git a/arch/arm/src/mx8mp/mx8mp_serial.c b/arch/arm/src/mx8mp/mx8mp_serial.c
index 587997c411..ba54e5caf4 100644
--- a/arch/arm/src/mx8mp/mx8mp_serial.c
+++ b/arch/arm/src/mx8mp/mx8mp_serial.c
@@ -1051,7 +1051,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART_CONSOLE
   struct mx8mp_uart_s *priv = (struct mx8mp_uart_s *)CONSOLE_DEV.priv;
@@ -1065,8 +1065,6 @@ int up_putc(int ch)
   arm_lowputc(ch);
   mx8mp_restoreuartint(priv, ier);
 #endif
-
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -1113,14 +1111,12 @@ static inline void mx8mp_waittxready(void)
  * Public Functions
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef MX8MP_CONSOLE
   mx8mp_waittxready();
   putreg32((uint16_t)ch, MX8MP_CONSOLE + UART_TXD_OFFSET);
 #endif
-
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/nrf52/nrf52_serial.c b/arch/arm/src/nrf52/nrf52_serial.c
index de7b42b27a..b667be09f5 100644
--- a/arch/arm/src/nrf52/nrf52_serial.c
+++ b/arch/arm/src/nrf52/nrf52_serial.c
@@ -812,15 +812,13 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART_CONSOLE
   /* struct nrf52_dev_s *priv = (struct nrf52_dev_s *)CONSOLE_DEV.priv; */
 
   arm_lowputc(ch);
 #endif
-
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -833,12 +831,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART_CONSOLE
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* HAVE_UART_DEVICE && USE_SERIALDRIVER */
diff --git a/arch/arm/src/nrf53/nrf53_serial.c b/arch/arm/src/nrf53/nrf53_serial.c
index a5b478a297..7cb5983493 100644
--- a/arch/arm/src/nrf53/nrf53_serial.c
+++ b/arch/arm/src/nrf53/nrf53_serial.c
@@ -812,15 +812,13 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART_CONSOLE
   /* struct nrf53_dev_s *priv = (struct nrf53_dev_s *)CONSOLE_DEV.priv; */
 
   arm_lowputc(ch);
 #endif
-
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -833,12 +831,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART_CONSOLE
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* HAVE_UART_DEVICE && USE_SERIALDRIVER */
diff --git a/arch/arm/src/nrf91/nrf91_serial.c b/arch/arm/src/nrf91/nrf91_serial.c
index adcbb433f9..1e9c39b169 100644
--- a/arch/arm/src/nrf91/nrf91_serial.c
+++ b/arch/arm/src/nrf91/nrf91_serial.c
@@ -812,15 +812,13 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART_CONSOLE
   /* struct nrf91_dev_s *priv = (struct nrf91_dev_s *)CONSOLE_DEV.priv; */
 
   arm_lowputc(ch);
 #endif
-
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -833,12 +831,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART_CONSOLE
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* HAVE_UART_DEVICE && USE_SERIALDRIVER */
diff --git a/arch/arm/src/nuc1xx/nuc_serial.c b/arch/arm/src/nuc1xx/nuc_serial.c
index ac9657fd89..0659a05c9f 100644
--- a/arch/arm/src/nuc1xx/nuc_serial.c
+++ b/arch/arm/src/nuc1xx/nuc_serial.c
@@ -1049,7 +1049,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_CONSOLE
   struct nuc_dev_s *priv = (struct nuc_dev_s *)CONSOLE_DEV.priv;
@@ -1061,8 +1061,6 @@ int up_putc(int ch)
 #ifdef HAVE_CONSOLE
   up_restoreuartint(priv, ier);
 #endif
-
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER && HAVE_UART */
@@ -1075,12 +1073,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART
   nuc_lowputc((uint32_t)ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER && HAVE_UART */
diff --git a/arch/arm/src/phy62xx/uart.c b/arch/arm/src/phy62xx/uart.c
index 1765bd13ec..e9a6e3fb8d 100644
--- a/arch/arm/src/phy62xx/uart.c
+++ b/arch/arm/src/phy62xx/uart.c
@@ -1127,10 +1127,9 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   hal_uart_send_byte(UART0, (char)ch);
-  return ch;
 }
 
 struct h4uart_param_s
diff --git a/arch/arm/src/rp2040/rp2040_serial.c b/arch/arm/src/rp2040/rp2040_serial.c
index d0c9ec7465..072f6274ad 100644
--- a/arch/arm/src/rp2040/rp2040_serial.c
+++ b/arch/arm/src/rp2040/rp2040_serial.c
@@ -1015,7 +1015,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_CONSOLE
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -1026,8 +1026,6 @@ int up_putc(int ch)
 #ifdef HAVE_CONSOLE
   up_restoreuartint(priv, ier);
 #endif
-
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -1040,12 +1038,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/rtl8720c/ameba_uart.c b/arch/arm/src/rtl8720c/ameba_uart.c
index 2b26791e4a..c63899d0ec 100644
--- a/arch/arm/src/rtl8720c/ameba_uart.c
+++ b/arch/arm/src/rtl8720c/ameba_uart.c
@@ -1074,12 +1074,11 @@ void arm_serialinit(void)
  ****************************************************************************/
 
 #ifdef HAVE_AMEBA_CONSOLE
-int up_putc(int ch)
+void up_putc(int ch)
 {
   struct ameba_s *priv = (struct ameba_s *)CONSOLE_DEV.priv;
 
   ameba_putc(priv, ch);
-  return ch;
 }
 
 #endif
diff --git a/arch/arm/src/s32k1xx/s32k1xx_serial.c b/arch/arm/src/s32k1xx/s32k1xx_serial.c
index c023b810c8..4716e15817 100644
--- a/arch/arm/src/s32k1xx/s32k1xx_serial.c
+++ b/arch/arm/src/s32k1xx/s32k1xx_serial.c
@@ -2544,7 +2544,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef CONSOLE_DEV
   struct s32k1xx_uart_s *priv =
@@ -2555,8 +2555,6 @@ int up_putc(int ch)
   s32k1xx_lowputc(ch);
   s32k1xx_restoreuartint(priv, ie);
 #endif
-
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -2569,13 +2567,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_LPUART > 0
   arm_lowputc(ch);
 #endif
-
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/s32k3xx/s32k3xx_serial.c b/arch/arm/src/s32k3xx/s32k3xx_serial.c
index edf05ffefc..8d44f460e3 100644
--- a/arch/arm/src/s32k3xx/s32k3xx_serial.c
+++ b/arch/arm/src/s32k3xx/s32k3xx_serial.c
@@ -4453,7 +4453,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef CONSOLE_DEV
   struct s32k3xx_uart_s *priv = (struct s32k3xx_uart_s *)&CONSOLE_DEV;
@@ -4463,8 +4463,6 @@ int up_putc(int ch)
   s32k3xx_lowputc(ch);
   s32k3xx_restoreuartint(priv, ie);
 #endif
-
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -4477,13 +4475,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_LPUART > 0
   arm_lowputc(ch);
 #endif
-
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/sam34/sam_lowputc.c b/arch/arm/src/sam34/sam_lowputc.c
index c381d067df..e6f5a19791 100644
--- a/arch/arm/src/sam34/sam_lowputc.c
+++ b/arch/arm/src/sam34/sam_lowputc.c
@@ -303,12 +303,11 @@ void arm_lowputc(char ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_CONSOLE
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 /****************************************************************************
diff --git a/arch/arm/src/sama5/sam_lowputc.c b/arch/arm/src/sama5/sam_lowputc.c
index 0efe8bd41b..e2fa599f50 100644
--- a/arch/arm/src/sama5/sam_lowputc.c
+++ b/arch/arm/src/sama5/sam_lowputc.c
@@ -315,14 +315,13 @@ void arm_lowputc(char ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if defined(SAMA5_HAVE_UART_CONSOLE) || defined(SAMA5_HAVE_USART_CONSOLE) || \
     defined(SAMA5_HAVE_FLEXCOM_CONSOLE) || defined(CONFIG_SAMA5_DBGU_CONSOLE)
 
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 /****************************************************************************
diff --git a/arch/arm/src/samd2l2/sam_serial.c b/arch/arm/src/samd2l2/sam_serial.c
index 67e32de58a..e9ee18b1bc 100644
--- a/arch/arm/src/samd2l2/sam_serial.c
+++ b/arch/arm/src/samd2l2/sam_serial.c
@@ -1037,7 +1037,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   irqstate_t flags;
@@ -1050,7 +1050,6 @@ int up_putc(int ch)
   sam_lowputc(ch);
   spin_unlock_irqrestore(NULL, flags);
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -1063,12 +1062,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   sam_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/samd5e5/sam_serial.c b/arch/arm/src/samd5e5/sam_serial.c
index 0376ccaa6d..f96feec0f1 100644
--- a/arch/arm/src/samd5e5/sam_serial.c
+++ b/arch/arm/src/samd5e5/sam_serial.c
@@ -1096,7 +1096,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   irqstate_t flags;
@@ -1109,7 +1109,6 @@ int up_putc(int ch)
   sam_lowputc(ch);
   spin_unlock_irqrestore(NULL, flags);
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -1122,12 +1121,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   sam_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/samv7/sam_lowputc.c b/arch/arm/src/samv7/sam_lowputc.c
index 3f512313c0..717662820f 100644
--- a/arch/arm/src/samv7/sam_lowputc.c
+++ b/arch/arm/src/samv7/sam_lowputc.c
@@ -209,12 +209,11 @@ void arm_lowputc(char ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 /****************************************************************************
diff --git a/arch/arm/src/stm32/stm32_serial.c b/arch/arm/src/stm32/stm32_serial.c
index b7094a7383..5f53144514 100644
--- a/arch/arm/src/stm32/stm32_serial.c
+++ b/arch/arm/src/stm32/stm32_serial.c
@@ -3627,7 +3627,7 @@ void stm32_serial_dma_poll(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_UART > 0
   struct up_dev_s *priv = g_uart_devs[CONSOLE_UART - 1];
@@ -3642,7 +3642,6 @@ int up_putc(int ch)
   arm_lowputc(ch);
   up_restoreusartint(priv, ie);
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -3655,12 +3654,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_UART > 0 || CONSOLE_LPUART > 0
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/stm32f0l0g0/stm32_serial_v1.c b/arch/arm/src/stm32f0l0g0/stm32_serial_v1.c
index 16915dd733..7bb31b5dad 100644
--- a/arch/arm/src/stm32f0l0g0/stm32_serial_v1.c
+++ b/arch/arm/src/stm32f0l0g0/stm32_serial_v1.c
@@ -2574,7 +2574,7 @@ void stm32serial_dmapoll(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_USART > 0
   struct stm32_serial_s *priv = g_uart_devs[CONSOLE_USART - 1];
@@ -2584,7 +2584,6 @@ int up_putc(int ch)
   arm_lowputc(ch);
   stm32serial_restoreusartint(priv, ie);
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -2597,13 +2596,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_USART > 0
   arm_lowputc(ch);
 #endif
-
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/stm32f0l0g0/stm32_serial_v2.c b/arch/arm/src/stm32f0l0g0/stm32_serial_v2.c
index 2b2d8ff601..6ccc4ad553 100644
--- a/arch/arm/src/stm32f0l0g0/stm32_serial_v2.c
+++ b/arch/arm/src/stm32f0l0g0/stm32_serial_v2.c
@@ -2007,7 +2007,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_USART > 0
   struct up_dev_s *priv = g_uart_devs[CONSOLE_USART - 1];
@@ -2018,7 +2018,6 @@ int up_putc(int ch)
   up_restoreusartint(priv, ie);
 
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -2031,12 +2030,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_USART > 0
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/stm32f7/stm32_serial.c b/arch/arm/src/stm32f7/stm32_serial.c
index 0d1716f688..894a0e48bb 100644
--- a/arch/arm/src/stm32f7/stm32_serial.c
+++ b/arch/arm/src/stm32f7/stm32_serial.c
@@ -3792,7 +3792,7 @@ void stm32_serial_dma_poll(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_UART > 0
   struct up_dev_s *priv = g_uart_devs[CONSOLE_UART - 1];
@@ -3802,7 +3802,6 @@ int up_putc(int ch)
   arm_lowputc(ch);
   up_restoreusartint(priv, ie);
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -3815,12 +3814,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_UART > 0
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/stm32h7/stm32_serial.c b/arch/arm/src/stm32h7/stm32_serial.c
index f799aeaec6..164aef0276 100644
--- a/arch/arm/src/stm32h7/stm32_serial.c
+++ b/arch/arm/src/stm32h7/stm32_serial.c
@@ -4001,7 +4001,7 @@ void stm32_serial_dma_poll(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_UART > 0
   struct up_dev_s *priv = g_uart_devs[CONSOLE_UART - 1];
@@ -4012,7 +4012,6 @@ int up_putc(int ch)
   up_restoreusartint(priv, ie);
 
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -4025,12 +4024,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_UART > 0
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/stm32l4/stm32l4_serial.c b/arch/arm/src/stm32l4/stm32l4_serial.c
index 0b068d03b4..8e030d02ee 100644
--- a/arch/arm/src/stm32l4/stm32l4_serial.c
+++ b/arch/arm/src/stm32l4/stm32l4_serial.c
@@ -3261,7 +3261,7 @@ void stm32l4_serial_dma_poll(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_UART > 0
   struct stm32l4_serial_s *priv = g_uart_devs[CONSOLE_UART - 1];
@@ -3271,7 +3271,6 @@ int up_putc(int ch)
   arm_lowputc(ch);
   stm32l4serial_restoreusartint(priv, ie);
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -3284,12 +3283,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_UART > 0
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/stm32l5/stm32l5_serial.c b/arch/arm/src/stm32l5/stm32l5_serial.c
index 2a518d29e4..960b29db45 100644
--- a/arch/arm/src/stm32l5/stm32l5_serial.c
+++ b/arch/arm/src/stm32l5/stm32l5_serial.c
@@ -3194,7 +3194,7 @@ void stm32l5_serial_dma_poll(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_UART > 0
   struct stm32l5_serial_s *priv = g_uart_devs[CONSOLE_UART - 1];
@@ -3204,7 +3204,6 @@ int up_putc(int ch)
   arm_lowputc(ch);
   stm32l5serial_restoreusartint(priv, ie);
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -3217,12 +3216,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_UART > 0
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/stm32u5/stm32_serial.c b/arch/arm/src/stm32u5/stm32_serial.c
index e642224d26..b5ddb511a6 100644
--- a/arch/arm/src/stm32u5/stm32_serial.c
+++ b/arch/arm/src/stm32u5/stm32_serial.c
@@ -3194,7 +3194,7 @@ void stm32_serial_dma_poll(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_UART > 0
   struct stm32_serial_s *priv = g_uart_devs[CONSOLE_UART - 1];
@@ -3204,7 +3204,6 @@ int up_putc(int ch)
   arm_lowputc(ch);
   stm32serial_restoreusartint(priv, ie);
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -3217,12 +3216,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_UART > 0
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/stm32wb/stm32wb_serial.c b/arch/arm/src/stm32wb/stm32wb_serial.c
index f6d614a9ea..69804719e7 100644
--- a/arch/arm/src/stm32wb/stm32wb_serial.c
+++ b/arch/arm/src/stm32wb/stm32wb_serial.c
@@ -2827,7 +2827,7 @@ void stm32wb_serial_dma_poll(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_UART > 0
   struct stm32wb_serial_s *priv = g_uart_devs[CONSOLE_UART - 1];
@@ -2837,7 +2837,6 @@ int up_putc(int ch)
   arm_lowputc(ch);
   stm32wb_serial_restoreusartint(priv, ie);
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -2850,12 +2849,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_UART > 0
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/stm32wl5/stm32wl5_serial.c b/arch/arm/src/stm32wl5/stm32wl5_serial.c
index d55b99c5af..604dd3993d 100644
--- a/arch/arm/src/stm32wl5/stm32wl5_serial.c
+++ b/arch/arm/src/stm32wl5/stm32wl5_serial.c
@@ -2928,7 +2928,7 @@ void stm32wl5_serial_dma_poll(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_UART > 0
   struct stm32wl5_serial_s *priv = g_uart_devs[CONSOLE_UART - 1];
@@ -2938,7 +2938,6 @@ int up_putc(int ch)
   arm_lowputc(ch);
   stm32wl5serial_restoreusartint(priv, ie);
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -2951,12 +2950,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #if CONSOLE_UART > 0
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/str71x/str71x_serial.c b/arch/arm/src/str71x/str71x_serial.c
index 6a72b0a613..53ddaddadd 100644
--- a/arch/arm/src/str71x/str71x_serial.c
+++ b/arch/arm/src/str71x/str71x_serial.c
@@ -950,7 +950,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_CONSOLE
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -963,7 +963,6 @@ int up_putc(int ch)
   up_waittxnotfull(priv);
   up_restoreuartint(priv, ier);
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -976,12 +975,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_CONSOLE
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/tiva/common/tiva_serial.c b/arch/arm/src/tiva/common/tiva_serial.c
index c223d38255..9b05adf72d 100644
--- a/arch/arm/src/tiva/common/tiva_serial.c
+++ b/arch/arm/src/tiva/common/tiva_serial.c
@@ -1572,7 +1572,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -1586,7 +1586,6 @@ int up_putc(int ch)
   up_waittxnotfull(priv);
   up_restoreuartint(priv, im);
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -1599,12 +1598,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/arm/src/tlsr82/tlsr82_serial.c b/arch/arm/src/tlsr82/tlsr82_serial.c
index 78f3b6062e..b95551266a 100644
--- a/arch/arm/src/tlsr82/tlsr82_serial.c
+++ b/arch/arm/src/tlsr82/tlsr82_serial.c
@@ -1591,11 +1591,9 @@ static inline int tlsr82_uart_lowputc(int ch)
  ****************************************************************************/
 
 #ifndef CONFIG_TLSR82_SPI_SYSLOG
-int up_putc(int ch)
+void up_putc(int ch)
 {
   tlsr82_uart_lowputc(ch);
-
-  return 0;
 }
 #endif
 
diff --git a/arch/arm/src/tlsr82/tlsr82_spi_console.c b/arch/arm/src/tlsr82/tlsr82_spi_console.c
index 6b4e3e09bd..b82a3a705a 100644
--- a/arch/arm/src/tlsr82/tlsr82_spi_console.c
+++ b/arch/arm/src/tlsr82/tlsr82_spi_console.c
@@ -324,10 +324,8 @@ void spi_console_init(void)
  ****************************************************************************/
 
 #ifdef CONFIG_TLSR82_SPI_SYSLOG
-int up_putc(int ch)
+void up_putc(int ch)
 {
   spi_putc((uint8_t)ch);
-
-  return 0;
 }
 #endif
diff --git a/arch/arm/src/tms570/tms570_lowputc.c b/arch/arm/src/tms570/tms570_lowputc.c
index deb907b7e2..c5a5695101 100644
--- a/arch/arm/src/tms570/tms570_lowputc.c
+++ b/arch/arm/src/tms570/tms570_lowputc.c
@@ -226,12 +226,11 @@ void arm_lowputc(char ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   arm_lowputc(ch);
 #endif
-  return ch;
 }
 
 /****************************************************************************
diff --git a/arch/arm/src/xmc4/xmc4_serial.c b/arch/arm/src/xmc4/xmc4_serial.c
index 08cb0f3a2a..133e780274 100644
--- a/arch/arm/src/xmc4/xmc4_serial.c
+++ b/arch/arm/src/xmc4/xmc4_serial.c
@@ -1120,7 +1120,7 @@ void arm_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART_CONSOLE
   struct xmc4_dev_s *priv = (struct xmc4_dev_s *)CONSOLE_DEV.priv;
@@ -1130,8 +1130,6 @@ int up_putc(int ch)
   arm_lowputc(ch);
   xmc4_restoreuartint(priv, ccr);
 #endif
-
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -1144,11 +1142,10 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART_CONSOLE
   arm_lowputc(ch);
-  return ch;
 #endif
 }
 
diff --git a/arch/arm64/src/a64/a64_serial.c b/arch/arm64/src/a64/a64_serial.c
index 20e6bee63d..35c36d5853 100644
--- a/arch/arm64/src/a64/a64_serial.c
+++ b/arch/arm64/src/a64/a64_serial.c
@@ -1412,14 +1412,13 @@ void arm64_earlyserialinit(void)
  *
  ***************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef CONSOLE_DEV
   struct uart_dev_s *dev = &CONSOLE_DEV;
 
   a64_uart_wait_send(dev, ch);
 #endif
-  return ch;
 }
 
 /***************************************************************************
diff --git a/arch/arm64/src/imx8/imx8qm_serial.c b/arch/arm64/src/imx8/imx8qm_serial.c
index 3d77b45801..c409b6829c 100644
--- a/arch/arm64/src/imx8/imx8qm_serial.c
+++ b/arch/arm64/src/imx8/imx8qm_serial.c
@@ -1049,12 +1049,11 @@ void arm64_earlyserialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   struct uart_dev_s *dev = &CONSOLE_DEV;
 
   imx8_send(dev, (uint8_t)ch);
-  return ch;
 }
 
 /****************************************************************************
diff --git a/arch/arm64/src/imx9/imx9_lpuart.c b/arch/arm64/src/imx9/imx9_lpuart.c
index 337d65b497..a53bef673d 100644
--- a/arch/arm64/src/imx9/imx9_lpuart.c
+++ b/arch/arm64/src/imx9/imx9_lpuart.c
@@ -2790,7 +2790,7 @@ void arm64_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef CONSOLE_DEV
   struct imx9_uart_s *priv = (struct imx9_uart_s *)&CONSOLE_DEV;
@@ -2798,7 +2798,7 @@ int up_putc(int ch)
 
   if (!CONSOLE_DEV.dev.isconsole)
     {
-      return ch;
+      return;
     }
 
   imx9_disableuartint(priv, &ie);
@@ -2808,5 +2808,4 @@ int up_putc(int ch)
 #ifdef CONSOLE_DEV
   imx9_restoreuartint(priv, ie);
 #endif
-  return ch;
 }
diff --git a/arch/arm64/src/rk3399/rk3399_serial.c b/arch/arm64/src/rk3399/rk3399_serial.c
index dad69170a7..2acd0bbbd2 100644
--- a/arch/arm64/src/rk3399/rk3399_serial.c
+++ b/arch/arm64/src/rk3399/rk3399_serial.c
@@ -1355,14 +1355,13 @@ void arm64_earlyserialinit(void)
  *
  ***************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef CONSOLE_DEV
   struct uart_dev_s *dev = &CONSOLE_DEV;
 
   a64_uart_wait_send(dev, ch);
 #endif
-  return ch;
 }
 
 /***************************************************************************
diff --git a/arch/arm64/src/zynq-mpsoc/zynq_serial.c b/arch/arm64/src/zynq-mpsoc/zynq_serial.c
index dacda08080..d5abc5c11a 100644
--- a/arch/arm64/src/zynq-mpsoc/zynq_serial.c
+++ b/arch/arm64/src/zynq-mpsoc/zynq_serial.c
@@ -1308,14 +1308,13 @@ void arm64_earlyserialinit(void)
  *
  ***************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef CONSOLE_DEV
   struct uart_dev_s *dev = &CONSOLE_DEV;
 
   zynq_uart_wait_send(dev, ch);
 #endif
-  return ch;
 }
 
 /***************************************************************************
diff --git a/arch/avr/src/at32uc3/at32uc3_serial.c b/arch/avr/src/at32uc3/at32uc3_serial.c
index 8a04696437..113651e88b 100644
--- a/arch/avr/src/at32uc3/at32uc3_serial.c
+++ b/arch/avr/src/at32uc3/at32uc3_serial.c
@@ -754,7 +754,7 @@ void avr_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -764,7 +764,6 @@ int up_putc(int ch)
   avr_lowputc(ch);
   up_restoreusartint(priv, imr);
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -777,12 +776,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   avr_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/avr/src/at90usb/at90usb_serial.c b/arch/avr/src/at90usb/at90usb_serial.c
index 8bd44890c8..fd7e743120 100644
--- a/arch/avr/src/at90usb/at90usb_serial.c
+++ b/arch/avr/src/at90usb/at90usb_serial.c
@@ -561,7 +561,7 @@ void avr_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   uint8_t imr;
@@ -570,7 +570,6 @@ int up_putc(int ch)
   avr_lowputc(ch);
   usart1_restoreusartint(imr);
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -583,12 +582,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   avr_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/avr/src/atmega/atmega_serial.c b/arch/avr/src/atmega/atmega_serial.c
index 0d72576050..71d01652d6 100644
--- a/arch/avr/src/atmega/atmega_serial.c
+++ b/arch/avr/src/atmega/atmega_serial.c
@@ -889,7 +889,7 @@ void avr_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   uint8_t imr;
@@ -908,8 +908,6 @@ int up_putc(int ch)
   usart1_restoreusartint(imr);
 #endif
 #endif
-
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -922,12 +920,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   avr_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/hc/src/m9s12/m9s12_serial.c b/arch/hc/src/m9s12/m9s12_serial.c
index 3e9fda857d..67e3cf0829 100644
--- a/arch/hc/src/m9s12/m9s12_serial.c
+++ b/arch/hc/src/m9s12/m9s12_serial.c
@@ -767,7 +767,7 @@ void hc_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_CONSOLE
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -780,7 +780,6 @@ int up_putc(int ch)
   up_waittxnotfull(priv);
   up_restoresciint(priv, im);
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -793,12 +792,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef CONFIG_ARCH_LOWPUTC
   hc_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/mips/src/pic32mx/pic32mx_serial.c b/arch/mips/src/pic32mx/pic32mx_serial.c
index 888be4dfc4..5ab802aafc 100644
--- a/arch/mips/src/pic32mx/pic32mx_serial.c
+++ b/arch/mips/src/pic32mx/pic32mx_serial.c
@@ -876,7 +876,7 @@ void mips_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   struct uart_dev_s *dev = (struct uart_dev_s *)&CONSOLE_DEV;
@@ -886,7 +886,6 @@ int up_putc(int ch)
   mips_lowputc(ch);
   up_restoreuartint(dev, imr);
 #endif
-  return ch;
 }
 
 /****************************************************************************
@@ -908,9 +907,8 @@ void mips_serialinit(void)
 {
 }
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
-  return ch;
 }
 
 #endif /* HAVE_UART_DEVICE */
@@ -924,12 +922,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   mips_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/mips/src/pic32mz/pic32mz_serial.c b/arch/mips/src/pic32mz/pic32mz_serial.c
index 0cca1217a8..52ffc0473b 100644
--- a/arch/mips/src/pic32mz/pic32mz_serial.c
+++ b/arch/mips/src/pic32mz/pic32mz_serial.c
@@ -1413,7 +1413,7 @@ void mips_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   struct uart_dev_s *dev = (struct uart_dev_s *)&CONSOLE_DEV;
@@ -1423,7 +1423,6 @@ int up_putc(int ch)
   mips_lowputc(ch);
   up_restoreuartint(dev, imr);
 #endif
-  return ch;
 }
 
 /****************************************************************************
@@ -1445,9 +1444,8 @@ void mips_serialinit(void)
 {
 }
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
-  return ch;
 }
 
 #endif /* HAVE_UART_DEVICE */
@@ -1461,12 +1459,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   mips_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/misoc/src/common/misoc_serial.c b/arch/misoc/src/common/misoc_serial.c
index ab0eae52d2..ad62240bfd 100644
--- a/arch/misoc/src/common/misoc_serial.c
+++ b/arch/misoc/src/common/misoc_serial.c
@@ -541,7 +541,7 @@ void misoc_earlyserialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   struct uart_dev_s *dev = (struct uart_dev_s *)&CONSOLE_DEV;
@@ -551,7 +551,6 @@ int up_putc(int ch)
   misoc_lowputc(ch);
   misoc_restoreuartint(dev, imr);
 #endif
-  return ch;
 }
 
 /****************************************************************************
@@ -574,9 +573,8 @@ void misoc_serial_initialize(void)
 {
 }
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
-  return ch;
 }
 
 #endif /* HAVE_UART_DEVICE */
@@ -590,13 +588,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   misoc_lowputc(ch);
 #endif
-
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/or1k/src/mor1kx/mor1kx_serial.c b/arch/or1k/src/mor1kx/mor1kx_serial.c
index dc0b0b3d81..04f443d38b 100644
--- a/arch/or1k/src/mor1kx/mor1kx_serial.c
+++ b/arch/or1k/src/mor1kx/mor1kx_serial.c
@@ -106,7 +106,7 @@ void or1k_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   irqstate_t flags;
@@ -121,5 +121,4 @@ int up_putc(int ch)
 
   spin_unlock_irqrestore(NULL, flags);
 #endif
-  return ch;
 }
diff --git a/arch/renesas/src/m16c/m16c_serial.c b/arch/renesas/src/m16c/m16c_serial.c
index c374191813..1d9d779c2e 100644
--- a/arch/renesas/src/m16c/m16c_serial.c
+++ b/arch/renesas/src/m16c/m16c_serial.c
@@ -1094,7 +1094,7 @@ void renesas_consoleinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIALCONSOLE
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -1107,7 +1107,6 @@ int up_putc(int ch)
   up_waittxready(priv);
   up_restoreuartint(priv, ucon);
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -1120,12 +1119,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIALCONSOLE
   renesas_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/renesas/src/rx65n/rx65n_serial.c b/arch/renesas/src/rx65n/rx65n_serial.c
index 6cffba54a2..09195c9cb2 100644
--- a/arch/renesas/src/rx65n/rx65n_serial.c
+++ b/arch/renesas/src/rx65n/rx65n_serial.c
@@ -1692,7 +1692,7 @@ void renesas_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_CONSOLE
   struct up_dev_s *priv;
@@ -1705,7 +1705,6 @@ int up_putc(int ch)
   up_waittxready(priv);
   up_restoresciint(priv, scr);
 #endif
-  return ch;
 }
 #else /* USE_SERIALDRIVER */
 
@@ -1717,12 +1716,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_CONSOLE
   renesas_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/renesas/src/sh1/sh1_serial.c b/arch/renesas/src/sh1/sh1_serial.c
index dcf2eada73..6d083989cd 100644
--- a/arch/renesas/src/sh1/sh1_serial.c
+++ b/arch/renesas/src/sh1/sh1_serial.c
@@ -880,7 +880,7 @@ void renesas_consoleinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_CONSOLE
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -893,7 +893,6 @@ int up_putc(int ch)
   up_waittxready(priv);
   up_restoresciint(priv, scr);
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -906,12 +905,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_CONSOLE
   renesas_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/risc-v/src/bl602/bl602_serial.c b/arch/risc-v/src/bl602/bl602_serial.c
index 66ffa78699..163f3a7c82 100644
--- a/arch/risc-v/src/bl602/bl602_serial.c
+++ b/arch/risc-v/src/bl602/bl602_serial.c
@@ -886,7 +886,7 @@ void riscv_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   irqstate_t flags = spin_lock_irqsave(NULL);
@@ -894,7 +894,6 @@ int up_putc(int ch)
   riscv_lowputc(ch);
   spin_unlock_irqrestore(NULL, flags);
 #endif
-  return ch;
 }
 
 /****************************************************************************
@@ -917,9 +916,8 @@ void riscv_serialinit(void)
 {
 }
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
-  return ch;
 }
 
 #endif /* HAVE_UART_DEVICE */
@@ -933,12 +931,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   riscv_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/risc-v/src/bl808/bl808_serial.c b/arch/risc-v/src/bl808/bl808_serial.c
index 843d54651c..d0840d6cef 100644
--- a/arch/risc-v/src/bl808/bl808_serial.c
+++ b/arch/risc-v/src/bl808/bl808_serial.c
@@ -1004,7 +1004,7 @@ void bl808_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   struct bl808_uart_s *priv = CONSOLE_DEV.priv;
   uint8_t uart_idx = priv->config.idx;
@@ -1016,5 +1016,4 @@ int up_putc(int ch)
   putreg32(ch, BL808_UART_FIFO_WDATA(uart_idx));
 
   leave_critical_section(flags);
-  return ch;
 }
diff --git a/arch/risc-v/src/c906/c906_serial.c b/arch/risc-v/src/c906/c906_serial.c
index fe6e0c5ec1..af3c34f67d 100644
--- a/arch/risc-v/src/c906/c906_serial.c
+++ b/arch/risc-v/src/c906/c906_serial.c
@@ -663,7 +663,7 @@ void riscv_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -673,7 +673,6 @@ int up_putc(int ch)
   riscv_lowputc(ch);
   up_restoreuartint(priv, imr);
 #endif
-  return ch;
 }
 
 /****************************************************************************
@@ -696,9 +695,8 @@ void riscv_serialinit(void)
 {
 }
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
-  return ch;
 }
 
 #endif /* HAVE_UART_DEVICE */
@@ -712,12 +710,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   riscv_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/risc-v/src/common/espressif/esp_serial.c b/arch/risc-v/src/common/espressif/esp_serial.c
index 88161dad2f..3b62cbc7f2 100644
--- a/arch/risc-v/src/common/espressif/esp_serial.c
+++ b/arch/risc-v/src/common/espressif/esp_serial.c
@@ -1147,7 +1147,7 @@ void riscv_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef CONSOLE_UART
   uint32_t int_status;
@@ -1160,7 +1160,6 @@ int up_putc(int ch)
 #ifdef CONSOLE_UART
   esp_lowputc_restore_all_uart_int(CONSOLE_DEV.priv, &int_status);
 #endif
-  return ch;
 }
 
 #else /* HAVE_UART_DEVICE */
@@ -1187,9 +1186,8 @@ void riscv_serialinit(void)
 {
 }
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
-  return ch;
 }
 
 #endif /* HAVE_UART_DEVICE */
@@ -1211,13 +1209,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   riscv_lowputc(ch);
 #endif /* HAVE_SERIAL_CONSOLE */
-
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/risc-v/src/esp32c3-legacy/esp32c3_serial.c b/arch/risc-v/src/esp32c3-legacy/esp32c3_serial.c
index 5c1ab90b06..2541e5f896 100644
--- a/arch/risc-v/src/esp32c3-legacy/esp32c3_serial.c
+++ b/arch/risc-v/src/esp32c3-legacy/esp32c3_serial.c
@@ -1102,7 +1102,7 @@ void riscv_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef CONSOLE_UART
   uint32_t int_status;
@@ -1115,7 +1115,6 @@ int up_putc(int ch)
 #ifdef CONSOLE_UART
   esp32c3_lowputc_restore_all_uart_int(CONSOLE_DEV.priv, &int_status);
 #endif
-  return ch;
 }
 
 #endif /* HAVE_UART_DEVICE */
@@ -1130,7 +1129,7 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef CONSOLE_UART
   uint32_t int_status;
@@ -1143,7 +1142,6 @@ int up_putc(int ch)
 #ifdef CONSOLE_UART
   esp32c3_lowputc_restore_all_uart_int(CONSOLE_DEV.priv, &int_status);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/risc-v/src/fe310/fe310_serial.c b/arch/risc-v/src/fe310/fe310_serial.c
index b0d2a434c7..3d1dd8db66 100644
--- a/arch/risc-v/src/fe310/fe310_serial.c
+++ b/arch/risc-v/src/fe310/fe310_serial.c
@@ -653,7 +653,7 @@ void riscv_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -663,7 +663,6 @@ int up_putc(int ch)
   riscv_lowputc(ch);
   up_restoreuartint(priv, imr);
 #endif
-  return ch;
 }
 
 /****************************************************************************
@@ -686,9 +685,8 @@ void riscv_serialinit(void)
 {
 }
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
-  return ch;
 }
 
 #endif /* HAVE_UART_DEVICE */
@@ -702,12 +700,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   riscv_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/risc-v/src/hpm6000/hpm_serial.c b/arch/risc-v/src/hpm6000/hpm_serial.c
index ef4a46e06d..22b5732b1a 100644
--- a/arch/risc-v/src/hpm6000/hpm_serial.c
+++ b/arch/risc-v/src/hpm6000/hpm_serial.c
@@ -1292,7 +1292,7 @@ void riscv_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef CONSOLE_DEV
   struct hpm_uart_s *priv = (struct hpm_uart_s *)CONSOLE_DEV.dev.priv;
@@ -1302,7 +1302,6 @@ int up_putc(int ch)
   hpm_lowputc(ch);
   hpm_restoreuartint(priv, im);
 #endif
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -1315,12 +1314,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_UART_CONSOLE
   riscv_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/risc-v/src/hpm6750/hpm6750_serial.c b/arch/risc-v/src/hpm6750/hpm6750_serial.c
index dd2de33c9a..1fb2bfa693 100644
--- a/arch/risc-v/src/hpm6750/hpm6750_serial.c
+++ b/arch/risc-v/src/hpm6750/hpm6750_serial.c
@@ -838,7 +838,7 @@ void riscv_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -848,7 +848,6 @@ int up_putc(int ch)
   riscv_lowputc(ch);
   up_restoreuartint(priv, imr);
 #endif
-  return ch;
 }
 
 /****************************************************************************
@@ -871,9 +870,8 @@ void riscv_serialinit(void)
 {
 }
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
-  return ch;
 }
 
 #endif /* HAVE_UART_DEVICE */
@@ -887,12 +885,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   riscv_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/risc-v/src/k210/k210_serial.c b/arch/risc-v/src/k210/k210_serial.c
index 7af73bd02f..5dbb5b6824 100644
--- a/arch/risc-v/src/k210/k210_serial.c
+++ b/arch/risc-v/src/k210/k210_serial.c
@@ -653,7 +653,7 @@ void riscv_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -663,7 +663,6 @@ int up_putc(int ch)
   riscv_lowputc(ch);
   up_restoreuartint(priv, imr);
 #endif
-  return ch;
 }
 
 /****************************************************************************
@@ -686,9 +685,8 @@ void riscv_serialinit(void)
 {
 }
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
-  return ch;
 }
 
 #endif /* HAVE_UART_DEVICE */
@@ -702,12 +700,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   riscv_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/risc-v/src/k230/k230_start.c b/arch/risc-v/src/k230/k230_start.c
index 37a8e2ee36..301384e012 100644
--- a/arch/risc-v/src/k230/k230_start.c
+++ b/arch/risc-v/src/k230/k230_start.c
@@ -191,10 +191,7 @@ void riscv_serialinit(void)
 }
 
 #ifdef CONFIG_RPMSG_UART_CONSOLE
-int up_putc(int ch)
+void up_putc(int ch)
 {
-  /* place holder for now */
-
-  return ch;
 }
 #endif
diff --git a/arch/risc-v/src/litex/litex_serial.c b/arch/risc-v/src/litex/litex_serial.c
index 6716756f4a..1c1b821f6b 100644
--- a/arch/risc-v/src/litex/litex_serial.c
+++ b/arch/risc-v/src/litex/litex_serial.c
@@ -685,7 +685,7 @@ void riscv_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -695,7 +695,6 @@ int up_putc(int ch)
   riscv_lowputc(ch);
   up_restoreuartint(priv, imr);
 #endif
-  return ch;
 }
 
 /****************************************************************************
@@ -718,9 +717,8 @@ void riscv_serialinit(void)
 {
 }
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
-  return ch;
 }
 
 #endif /* HAVE_UART_DEVICE */
@@ -734,12 +732,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   riscv_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/risc-v/src/mpfs/mpfs_serial.c b/arch/risc-v/src/mpfs/mpfs_serial.c
index 7f79d10bfc..309e1b4164 100644
--- a/arch/risc-v/src/mpfs/mpfs_serial.c
+++ b/arch/risc-v/src/mpfs/mpfs_serial.c
@@ -1245,7 +1245,7 @@ void riscv_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -1253,7 +1253,7 @@ int up_putc(int ch)
 
   if (!CONSOLE_DEV.isconsole)
     {
-      return ch;
+      return;
     }
 
   up_disableuartint(priv, &ier);
@@ -1263,7 +1263,6 @@ int up_putc(int ch)
 #ifdef HAVE_SERIAL_CONSOLE
   up_restoreuartint(priv, ier);
 #endif
-  return ch;
 }
 
 /****************************************************************************
@@ -1286,9 +1285,8 @@ void riscv_serialinit(void)
 {
 }
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
-  return ch;
 }
 
 #endif /* HAVE_UART_DEVICE */
@@ -1302,12 +1300,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   riscv_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/risc-v/src/rv32m1/rv32m1_serial.c b/arch/risc-v/src/rv32m1/rv32m1_serial.c
index a6a5043a62..2425f7d1ca 100644
--- a/arch/risc-v/src/rv32m1/rv32m1_serial.c
+++ b/arch/risc-v/src/rv32m1/rv32m1_serial.c
@@ -1133,7 +1133,7 @@ void riscv_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef CONSOLE_DEV
   struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
@@ -1143,7 +1143,6 @@ int up_putc(int ch)
   riscv_lowputc(ch);
   up_restoreuartint(priv, im);
 #endif
-  return ch;
 }
 
 #ifdef HAVE_SERIAL_CONSOLE
diff --git a/arch/sim/src/sim/sim_uart.c b/arch/sim/src/sim/sim_uart.c
index 54bc95dc8e..248d814de9 100644
--- a/arch/sim/src/sim/sim_uart.c
+++ b/arch/sim/src/sim/sim_uart.c
@@ -786,11 +786,10 @@ void up_nputs(const char *str, size_t len)
  * Name: up_putc
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef USE_DEVCONSOLE
   char c = ch;
   up_nputs(&c, 1);
 #endif
-  return 0;
 }
diff --git a/arch/sparc/src/bm3803/bm3803-serial.c b/arch/sparc/src/bm3803/bm3803-serial.c
index 4aef048d57..e6fb7e1d38 100644
--- a/arch/sparc/src/bm3803/bm3803-serial.c
+++ b/arch/sparc/src/bm3803/bm3803-serial.c
@@ -870,7 +870,7 @@ void sparc_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   struct uart_dev_s *dev = (struct uart_dev_s *)&CONSOLE_DEV;
@@ -880,7 +880,6 @@ int up_putc(int ch)
   sparc_lowputc(ch);
   up_restoreuartint(dev, imr);
 #endif
-  return ch;
 }
 
 /****************************************************************************
@@ -902,9 +901,8 @@ void sparc_serialinit(void)
 {
 }
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
-  return ch;
 }
 
 #endif /* HAVE_UART_DEVICE */
@@ -918,12 +916,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   sparc_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/sparc/src/bm3823/bm3823-serial.c b/arch/sparc/src/bm3823/bm3823-serial.c
index bd0f542bbb..4bfce9656d 100644
--- a/arch/sparc/src/bm3823/bm3823-serial.c
+++ b/arch/sparc/src/bm3823/bm3823-serial.c
@@ -865,7 +865,7 @@ void sparc_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   struct uart_dev_s *dev = (struct uart_dev_s *)&CONSOLE_DEV;
@@ -875,7 +875,6 @@ int up_putc(int ch)
   sparc_lowputc(ch);
   up_restoreuartint(dev, imr);
 #endif
-  return ch;
 }
 
 /****************************************************************************
@@ -897,9 +896,8 @@ void sparc_serialinit(void)
 {
 }
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
-  return ch;
 }
 
 #endif /* HAVE_UART_DEVICE */
@@ -913,12 +911,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   sparc_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/sparc/src/s698pm/s698pm-serial.c b/arch/sparc/src/s698pm/s698pm-serial.c
index f68573c6fd..89675d4034 100644
--- a/arch/sparc/src/s698pm/s698pm-serial.c
+++ b/arch/sparc/src/s698pm/s698pm-serial.c
@@ -951,7 +951,7 @@ void sparc_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   struct uart_dev_s *dev = (struct uart_dev_s *)&CONSOLE_DEV;
@@ -961,7 +961,6 @@ int up_putc(int ch)
   sparc_lowputc(ch);
   up_restoreuartint(dev, imr);
 #endif
-  return ch;
 }
 
 /****************************************************************************
@@ -983,9 +982,8 @@ void sparc_serialinit(void)
 {
 }
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
-  return ch;
 }
 
 #endif /* HAVE_UART_DEVICE */
@@ -999,12 +997,11 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   sparc_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/tricore/src/tc3xx/tc3xx_serial.c b/arch/tricore/src/tc3xx/tc3xx_serial.c
index 31bf3db75f..4edb62de90 100644
--- a/arch/tricore/src/tc3xx/tc3xx_serial.c
+++ b/arch/tricore/src/tc3xx/tc3xx_serial.c
@@ -722,11 +722,10 @@ void tricore_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   tricore_lowputc(ch);
 #endif
-  return ch;
 }
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/x86/src/qemu/qemu_serial.c b/arch/x86/src/qemu/qemu_serial.c
index eb7d0eac4a..5fe1ec53f4 100644
--- a/arch/x86/src/qemu/qemu_serial.c
+++ b/arch/x86/src/qemu/qemu_serial.c
@@ -73,10 +73,9 @@ void uart_putreg(struct u16550_s *priv,
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   x86_lowputc(ch);
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/x86_64/src/intel64/intel64_serial.c b/arch/x86_64/src/intel64/intel64_serial.c
index 58f0a254e2..780fe1a4e8 100644
--- a/arch/x86_64/src/intel64/intel64_serial.c
+++ b/arch/x86_64/src/intel64/intel64_serial.c
@@ -88,10 +88,9 @@ void up_lowputc(char ch)
   fb_putc(ch);
 }
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   up_lowputc(ch);
-  return ch;
 }
 #endif
 
diff --git a/arch/xtensa/src/esp32/esp32_serial.c b/arch/xtensa/src/esp32/esp32_serial.c
index 875b3679a1..981d310130 100644
--- a/arch/xtensa/src/esp32/esp32_serial.c
+++ b/arch/xtensa/src/esp32/esp32_serial.c
@@ -2114,7 +2114,7 @@ void xtensa_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   uint32_t intena;
@@ -2126,7 +2126,5 @@ int up_putc(int ch)
 
   esp32_restoreuartint(CONSOLE_DEV.priv, intena);
 #endif
-
-  return ch;
 }
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/xtensa/src/esp32s2/esp32s2_serial.c b/arch/xtensa/src/esp32s2/esp32s2_serial.c
index 20ee55dee7..a026de48ac 100644
--- a/arch/xtensa/src/esp32s2/esp32s2_serial.c
+++ b/arch/xtensa/src/esp32s2/esp32s2_serial.c
@@ -1119,7 +1119,7 @@ void xtensa_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   uint32_t int_status;
@@ -1128,7 +1128,6 @@ int up_putc(int ch)
   xtensa_lowputc(ch);
   esp32s2_lowputc_restore_all_uart_int(CONSOLE_DEV.priv, &int_status);
 #endif
-  return ch;
 }
 
 #else /* HAVE_UART_DEVICE */
@@ -1155,9 +1154,8 @@ void xtensa_serialinit(void)
 {
 }
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
-  return ch;
 }
 
 #endif /* HAVE_UART_DEVICE */
@@ -1173,14 +1171,13 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
   uint32_t int_status;
 
   xtensa_lowputc(ch);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/xtensa/src/esp32s3/esp32s3_serial.c b/arch/xtensa/src/esp32s3/esp32s3_serial.c
index 076f272a4e..880fcbf4e4 100644
--- a/arch/xtensa/src/esp32s3/esp32s3_serial.c
+++ b/arch/xtensa/src/esp32s3/esp32s3_serial.c
@@ -1210,7 +1210,7 @@ void xtensa_serialinit(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef CONSOLE_UART
   uint32_t int_status;
@@ -1223,7 +1223,6 @@ int up_putc(int ch)
 #ifdef CONSOLE_UART
   esp32s3_lowputc_restore_all_uart_int(CONSOLE_DEV.priv, &int_status);
 #endif
-  return ch;
 }
 
 #endif /* HAVE_UART_DEVICE */
@@ -1238,7 +1237,7 @@ int up_putc(int ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef CONSOLE_UART
   uint32_t int_status;
@@ -1251,7 +1250,6 @@ int up_putc(int ch)
 #ifdef CONSOLE_UART
   esp32s3_lowputc_restore_all_uart_int(CONSOLE_DEV.priv, &int_status);
 #endif
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/z16/src/z16f/z16f_serial.c b/arch/z16/src/z16f/z16f_serial.c
index b590c90624..00009ea396 100644
--- a/arch/z16/src/z16f/z16f_serial.c
+++ b/arch/z16/src/z16f/z16f_serial.c
@@ -742,7 +742,7 @@ void z16_serialinit(void)
  ****************************************************************************/
 
 #ifdef CONSOLE_DEV
-int up_putc(int ch)
+void up_putc(int ch)
 {
   uint8_t  state;
 
@@ -765,7 +765,6 @@ int up_putc(int ch)
    */
 
   z16f_restoreuartirq(&CONSOLE_DEV, state);
-  return ch;
 }
 #endif
 
@@ -810,12 +809,11 @@ static void z16f_putc(int ch)
  * Name: up_putc
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   /* Output character */
 
   z16f_putc(ch);
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/z80/src/ez80/ez80_serial.c b/arch/z80/src/ez80/ez80_serial.c
index 19e7dbdf71..4913717e92 100644
--- a/arch/z80/src/ez80/ez80_serial.c
+++ b/arch/z80/src/ez80/ez80_serial.c
@@ -733,7 +733,7 @@ void z80_serial_initialize(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef CONSOLE_DEV
   FAR struct ez80_dev_s *priv = (FAR struct ez80_dev_s *)CONSOLE_DEV.priv;
@@ -750,7 +750,6 @@ int up_putc(int ch)
 
   ez80_waittxready(priv);
   ez80_restoreuartint(priv, ier);
-  return ch;
 #endif
 }
 
@@ -794,12 +793,11 @@ static void ez80_putc(int ch)
  * Name: up_putc
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   /* Output character */
 
   ez80_putc(ch);
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/z80/src/z180/z180_lowserial.c b/arch/z80/src/z180/z180_lowserial.c
index d5464a66c8..77658ed5bb 100644
--- a/arch/z80/src/z180/z180_lowserial.c
+++ b/arch/z80/src/z180/z180_lowserial.c
@@ -58,13 +58,12 @@
 #ifdef USE_SERIALDRIVER
 int z80_lowputc(int ch)
 #else
-int up_putc(int ch)
+void up_putc(int ch)
 #endif
 {
   /* Output the character */
 
   z180_putc(ch);
-  return ch;
 }
 
 #endif /* HAVE_SERIAL */
diff --git a/arch/z80/src/z180/z180_scc.c b/arch/z80/src/z180/z180_scc.c
index 5034f3c9d5..daebc3b005 100644
--- a/arch/z80/src/z180/z180_scc.c
+++ b/arch/z80/src/z180/z180_scc.c
@@ -595,7 +595,7 @@ void z80_serial_initialize(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
 #ifdef CONSOLE_DEV
   /* Disable [E]SCC interrupts and perform the low-level output */
@@ -603,7 +603,6 @@ int up_putc(int ch)
   z180_disableuartint(priv);
   z80_lowputc(ch);
   z180_restoreuartint(priv);
-  return ch;
 #endif
 }
 #endif /* USE_SERIALDRIVER */
diff --git a/arch/z80/src/z180/z180_serial.h b/arch/z80/src/z180/z180_serial.h
index 1999d0e72b..25b406567e 100644
--- a/arch/z80/src/z180/z180_serial.h
+++ b/arch/z80/src/z180/z180_serial.h
@@ -59,7 +59,7 @@ void z180_putc(uint8_t ch) __naked;
 #ifdef USE_SERIALDRIVER
 int z80_lowputc(int ch);
 #else
-int up_putc(int ch);
+void up_putc(int ch);
 #  define z80_lowputc(ch) up_putc(ch)
 #endif
 
diff --git a/arch/z80/src/z8/z8_serial.c b/arch/z80/src/z8/z8_serial.c
index e53d10df7a..d0a432e81c 100644
--- a/arch/z80/src/z8/z8_serial.c
+++ b/arch/z80/src/z8/z8_serial.c
@@ -724,7 +724,7 @@ void z80_serial_initialize(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   uint8_t  state;
 
@@ -744,7 +744,6 @@ int up_putc(int ch)
    */
 
   z8_restoreuartirq(&CONSOLE_DEV, state);
-  return ch;
 }
 
 #else /* USE_SERIALDRIVER */
@@ -796,12 +795,11 @@ static void z8_putc(int ch)
  * Name: up_putc
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   /* Output character */
 
   z8_putc(ch);
-  return ch;
 }
 
 #endif /* USE_SERIALDRIVER */
diff --git a/boards/renesas/m16c/skp16c26/src/m16c_lcdconsole.c b/boards/renesas/m16c/skp16c26/src/m16c_lcdconsole.c
index cf13b00ba5..907e097ed3 100644
--- a/boards/renesas/m16c/skp16c26/src/m16c_lcdconsole.c
+++ b/boards/renesas/m16c/skp16c26/src/m16c_lcdconsole.c
@@ -116,10 +116,9 @@ void renesas_lowputc(char ch)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   up_lcdputc(ch);
-  return ch;
 }
 
 #endif /* !HAVE_SERIALCONSOLE && CONFIG_SLCD && CONFIG_SLCD_CONSOLE */
diff --git a/boards/z80/z80/z80sim/src/z80_serial.c b/boards/z80/z80/z80sim/src/z80_serial.c
index f04ff5513c..05fb56ec1a 100644
--- a/boards/z80/z80/z80sim/src/z80_serial.c
+++ b/boards/z80/z80/z80sim/src/z80_serial.c
@@ -318,7 +318,7 @@ void z80_serial_initialize(void)
  *
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   z80_lowputc(ch);
   return 0;
diff --git a/drivers/serial/serial_cmsdk.c b/drivers/serial/serial_cmsdk.c
index 7fdbfe72ee..e488a598d3 100644
--- a/drivers/serial/serial_cmsdk.c
+++ b/drivers/serial/serial_cmsdk.c
@@ -772,7 +772,7 @@ void cmsdk_serialinit(void)
  ****************************************************************************/
 
 #ifdef HAVE_CMSDK_CONSOLE
-int up_putc(int ch)
+void up_putc(int ch)
 {
   FAR struct uart_cmsdk_s *priv = CONSOLE_DEV.priv;
   uint32_t ier;
@@ -780,6 +780,5 @@ int up_putc(int ch)
   ier = uart_cmsdk_disableuartint(priv);
   uart_cmsdk_putc(priv, ch);
   uart_cmsdk_restoreuartint(priv, ier);
-  return ch;
 }
 #endif
diff --git a/drivers/serial/uart_16550.c b/drivers/serial/uart_16550.c
index fba8c8e453..1547551815 100644
--- a/drivers/serial/uart_16550.c
+++ b/drivers/serial/uart_16550.c
@@ -1700,13 +1700,11 @@ void u16550_serialinit(void)
  ****************************************************************************/
 
 #ifdef HAVE_16550_CONSOLE
-int up_putc(int ch)
+void up_putc(int ch)
 {
   FAR struct u16550_s *priv = (FAR struct u16550_s *)CONSOLE_DEV.priv;
 
   u16550_putc(priv, ch);
-
-  return ch;
 }
 #endif
 
diff --git a/drivers/serial/uart_hostfs.c b/drivers/serial/uart_hostfs.c
index 32a459c9c9..0edb0e9ba5 100644
--- a/drivers/serial/uart_hostfs.c
+++ b/drivers/serial/uart_hostfs.c
@@ -293,10 +293,9 @@ void uart_hostfs_init(void)
   uart_register("/dev/console", &g_uart_hostfs_dev);
 }
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   FAR struct uart_dev_s *dev = &g_uart_hostfs_dev;
 
   uart_hostfs_send(dev, ch);
-  return ch;
 }
diff --git a/drivers/serial/uart_pci_16550.c b/drivers/serial/uart_pci_16550.c
index efe1d57061..7afc80e0ec 100644
--- a/drivers/serial/uart_pci_16550.c
+++ b/drivers/serial/uart_pci_16550.c
@@ -760,7 +760,7 @@ static int pci_u16550_probe(FAR struct pci_device_s *dev)
  *****************************************************************************/
 
 #ifdef CONFIG_16550_PCI_CONSOLE
-int up_putc(int ch)
+void up_putc(int ch)
 {
   irqstate_t flags;
 
@@ -768,7 +768,7 @@ int up_putc(int ch)
 
   if (CONSOLE_DEV.ops == NULL)
     {
-      return ch;
+      return;
     }
 
   /* All interrupts must be disabled to prevent re-entrancy and to prevent
@@ -778,8 +778,6 @@ int up_putc(int ch)
   flags = spin_lock_irqsave(NULL);
   u16550_putc(CONSOLE_DEV.priv, ch);
   spin_unlock_irqrestore(NULL, flags);
-
-  return ch;
 }
 #endif
 
diff --git a/drivers/serial/uart_pl011.c b/drivers/serial/uart_pl011.c
index c3fd3e0abd..4cd4f44640 100644
--- a/drivers/serial/uart_pl011.c
+++ b/drivers/serial/uart_pl011.c
@@ -1061,13 +1061,11 @@ void pl011_serialinit(void)
  ***************************************************************************/
 
 #ifdef HAVE_PL011_CONSOLE
-int up_putc(int ch)
+void up_putc(int ch)
 {
   FAR struct uart_dev_s *dev = &CONSOLE_DEV;
 
   pl011_putc(dev, ch);
-
-  return ch;
 }
 #endif
 
diff --git a/drivers/syslog/syslog_channel.c b/drivers/syslog/syslog_channel.c
index 8b7db478ef..95c0dea2db 100644
--- a/drivers/syslog/syslog_channel.c
+++ b/drivers/syslog/syslog_channel.c
@@ -235,10 +235,9 @@ static int syslog_default_putc(FAR syslog_channel_t *channel, int ch)
   UNUSED(channel);
 
 #  ifdef CONFIG_ARCH_LOWPUTC
-  return up_putc(ch);
-#  else
-  return ch;
+  up_putc(ch);
 #  endif
+  return ch;
 }
 
 static ssize_t syslog_default_write(FAR syslog_channel_t *channel,
diff --git a/drivers/virtio/virtio-serial.c b/drivers/virtio/virtio-serial.c
index 186c884f07..7a7a913f77 100644
--- a/drivers/virtio/virtio-serial.c
+++ b/drivers/virtio/virtio-serial.c
@@ -668,13 +668,11 @@ int virtio_register_serial_driver(void)
  * Name: up_putc
  ****************************************************************************/
 
-int up_putc(int ch)
+void up_putc(int ch)
 {
   if (g_virtio_console != NULL)
     {
       virtio_serial_send(g_virtio_console, ch);
     }
-
-  return ch;
 }
 #endif
diff --git a/include/nuttx/arch.h b/include/nuttx/arch.h
index 88d3022ce2..33b359441e 100644
--- a/include/nuttx/arch.h
+++ b/include/nuttx/arch.h
@@ -2824,7 +2824,7 @@ int arch_phy_irq(FAR const char *intf, xcpt_t handler, void *arg,
  *
  ****************************************************************************/
 
-int up_putc(int ch);
+void up_putc(int ch);
 
 /****************************************************************************
  * Name: up_puts
diff --git a/libs/libc/stream/lib_lowoutstream.c b/libs/libc/stream/lib_lowoutstream.c
index ffefea7cac..4a778c75b4 100644
--- a/libs/libc/stream/lib_lowoutstream.c
+++ b/libs/libc/stream/lib_lowoutstream.c
@@ -67,7 +67,9 @@ static void lowoutstream_putc(FAR struct lib_outstream_s *self, int ch)
 {
   DEBUGASSERT(self);
 
-  if (up_putc(ch) != EOF)
+  up_putc(ch);
+
+  if (ch != EOF)
     {
       self->nput++;
     }