diff --git a/arch/arm/src/dm320/dm320_serial.c b/arch/arm/src/dm320/dm320_serial.c
index dcceafb28a..19e5c9d7bd 100644
--- a/arch/arm/src/dm320/dm320_serial.c
+++ b/arch/arm/src/dm320/dm320_serial.c
@@ -268,6 +268,7 @@ static inline void up_waittxready(struct up_dev_s *priv)
 static inline void up_enablebreaks(struct up_dev_s *priv, bool enable)
 {
   uint16_t lcr = up_serialin(priv, UART_LCR);
+
   if (enable)
     {
       lcr |= UART_LCR_BOC;
@@ -276,6 +277,7 @@ static inline void up_enablebreaks(struct up_dev_s *priv, bool enable)
     {
       lcr &= ~UART_LCR_BOC;
     }
+
   up_serialout(priv, UART_LCR, lcr);
 }
 
diff --git a/arch/arm/src/lpc214x/lpc214x_serial.c b/arch/arm/src/lpc214x/lpc214x_serial.c
index 041f9b8c05..62b18ecfe3 100644
--- a/arch/arm/src/lpc214x/lpc214x_serial.c
+++ b/arch/arm/src/lpc214x/lpc214x_serial.c
@@ -272,6 +272,7 @@ static inline void up_waittxready(struct up_dev_s *priv)
 static inline void up_enablebreaks(struct up_dev_s *priv, bool enable)
 {
   uint8_t lcr = up_serialin(priv, LPC214X_UART_LCR_OFFSET);
+
   if (enable)
     {
       lcr |= LPC214X_LCR_BREAK_ENABLE;
@@ -280,6 +281,7 @@ static inline void up_enablebreaks(struct up_dev_s *priv, bool enable)
     {
       lcr &= ~LPC214X_LCR_BREAK_ENABLE;
     }
+
   up_serialout(priv, LPC214X_UART_LCR_OFFSET, lcr);
 }
 
diff --git a/arch/arm/src/lpc2378/lpc23xx_serial.c b/arch/arm/src/lpc2378/lpc23xx_serial.c
index 389d713284..9650a0827a 100644
--- a/arch/arm/src/lpc2378/lpc23xx_serial.c
+++ b/arch/arm/src/lpc2378/lpc23xx_serial.c
@@ -290,6 +290,7 @@ static inline void up_waittxready(struct up_dev_s *priv)
 static inline void up_enablebreaks(struct up_dev_s *priv, bool enable)
 {
   uint8_t lcr = up_serialin(priv, UART_LCR_OFFSET);
+
   if (enable)
     {
       lcr |= LCR_BREAK_ENABLE;
@@ -298,6 +299,7 @@ static inline void up_enablebreaks(struct up_dev_s *priv, bool enable)
     {
       lcr &= ~LCR_BREAK_ENABLE;
     }
+
   up_serialout(priv, UART_LCR_OFFSET, lcr);
 }
 
diff --git a/arch/arm/src/lpc43xx/lpc43_serial.c b/arch/arm/src/lpc43xx/lpc43_serial.c
index 0dda586af1..c12d65597b 100644
--- a/arch/arm/src/lpc43xx/lpc43_serial.c
+++ b/arch/arm/src/lpc43xx/lpc43_serial.c
@@ -551,6 +551,7 @@ static inline void up_restoreuartint(struct up_dev_s *priv, uint32_t ier)
 static inline void up_enablebreaks(struct up_dev_s *priv, bool enable)
 {
   uint32_t lcr = up_serialin(priv, LPC43_UART_LCR_OFFSET);
+
   if (enable)
     {
       lcr |= UART_LCR_BRK;
@@ -559,6 +560,7 @@ static inline void up_enablebreaks(struct up_dev_s *priv, bool enable)
     {
       lcr &= ~UART_LCR_BRK;
     }
+
   up_serialout(priv, LPC43_UART_LCR_OFFSET, lcr);
 }
 
diff --git a/arch/arm/src/stm32/stm32_serial.c b/arch/arm/src/stm32/stm32_serial.c
index 2e11d52609..73039dcf6d 100644
--- a/arch/arm/src/stm32/stm32_serial.c
+++ b/arch/arm/src/stm32/stm32_serial.c
@@ -2060,8 +2060,11 @@ static int up_ioctl(struct file *filep, int cmd, unsigned long arg)
 #ifdef CONFIG_USART_BREAKS
     case TIOCSBRK:  /* BSD compatibility: Turn break on, unconditionally */
       {
-        irqstate_t flags = enter_critical_section();
-        uint32_t cr2 = up_serialin(priv, STM32_USART_CR2_OFFSET);
+        uint32_t cr2;
+        irqstate_t flags;
+
+        flags = enter_critical_section();
+        cr2   = up_serialin(priv, STM32_USART_CR2_OFFSET);
         up_serialout(priv, STM32_USART_CR2_OFFSET, cr2 | USART_CR2_LINEN);
         leave_critical_section(flags);
       }
@@ -2069,9 +2072,11 @@ static int up_ioctl(struct file *filep, int cmd, unsigned long arg)
 
     case TIOCCBRK:  /* BSD compatibility: Turn break off, unconditionally */
       {
+        uint32_t cr2;
         irqstate_t flags;
+
         flags = enter_critical_section();
-        uint32_t cr1 = up_serialin(priv, STM32_USART_CR2_OFFSET);
+        cr2   = up_serialin(priv, STM32_USART_CR2_OFFSET);
         up_serialout(priv, STM32_USART_CR2_OFFSET, cr2 & ~USART_CR2_LINEN);
         leave_critical_section(flags);
       }
diff --git a/arch/arm/src/stm32f7/stm32_serial.c b/arch/arm/src/stm32f7/stm32_serial.c
index d62b78fd6e..78810f52f3 100644
--- a/arch/arm/src/stm32f7/stm32_serial.c
+++ b/arch/arm/src/stm32f7/stm32_serial.c
@@ -1967,8 +1967,11 @@ static int up_ioctl(struct file *filep, int cmd, unsigned long arg)
 #ifdef CONFIG_USART_BREAKS
     case TIOCSBRK:  /* BSD compatibility: Turn break on, unconditionally */
       {
-        irqstate_t flags = enter_critical_section();
-        uint32_t cr2 = up_serialin(priv, STM32_USART_CR2_OFFSET);
+        uint32_t cr2;
+        irqstate_t flags;
+
+        flags = enter_critical_section();
+        cr2   = up_serialin(priv, STM32_USART_CR2_OFFSET);
         up_serialout(priv, STM32_USART_CR2_OFFSET, cr2 | USART_CR2_LINEN);
         leave_critical_section(flags);
       }
@@ -1976,9 +1979,11 @@ static int up_ioctl(struct file *filep, int cmd, unsigned long arg)
 
     case TIOCCBRK:  /* BSD compatibility: Turn break off, unconditionally */
       {
+        uint32_t cr2;
         irqstate_t flags;
+
         flags = enter_critical_section();
-        uint32_t cr1 = up_serialin(priv, STM32_USART_CR2_OFFSET);
+        cr2   = up_serialin(priv, STM32_USART_CR2_OFFSET);
         up_serialout(priv, STM32_USART_CR2_OFFSET, cr2 & ~USART_CR2_LINEN);
         leave_critical_section(flags);
       }
diff --git a/arch/arm/src/stm32l4/stm32l4_serial.c b/arch/arm/src/stm32l4/stm32l4_serial.c
index 68e9e75245..8f68409dba 100644
--- a/arch/arm/src/stm32l4/stm32l4_serial.c
+++ b/arch/arm/src/stm32l4/stm32l4_serial.c
@@ -1723,8 +1723,11 @@ static int up_ioctl(struct file *filep, int cmd, unsigned long arg)
 #ifdef CONFIG_USART_BREAKS
     case TIOCSBRK:  /* BSD compatibility: Turn break on, unconditionally */
       {
-        irqstate_t flags = enter_critical_section();
-        uint32_t cr2 = up_serialin(priv, STM32L4_USART_CR2_OFFSET);
+        uint32_t cr2;
+        irqstate_t flags;
+
+        flags = enter_critical_section();
+        cr2   = up_serialin(priv, STM32L4_USART_CR2_OFFSET);
         up_serialout(priv, STM32L4_USART_CR2_OFFSET, cr2 | USART_CR2_LINEN);
         leave_critical_section(flags);
       }
@@ -1732,9 +1735,11 @@ static int up_ioctl(struct file *filep, int cmd, unsigned long arg)
 
     case TIOCCBRK:  /* BSD compatibility: Turn break off, unconditionally */
       {
+        uint32_t cr2;
         irqstate_t flags;
+
         flags = enter_critical_section();
-        uint32_t cr1 = up_serialin(priv, STM32L4_USART_CR2_OFFSET);
+        cr2   = up_serialin(priv, STM32L4_USART_CR2_OFFSET);
         up_serialout(priv, STM32L4_USART_CR2_OFFSET, cr2 & ~USART_CR2_LINEN);
         leave_critical_section(flags);
       }
diff --git a/drivers/serial/uart_16550.c b/drivers/serial/uart_16550.c
index 8b8eb82564..c7de1031a3 100644
--- a/drivers/serial/uart_16550.c
+++ b/drivers/serial/uart_16550.c
@@ -520,6 +520,7 @@ static inline void u16550_restoreuartint(FAR struct u16550_s *priv, uint32_t ier
 static inline void u16550_enablebreaks(FAR struct u16550_s *priv, bool enable)
 {
   uint32_t lcr = u16550_serialin(priv, UART_LCR_OFFSET);
+
   if (enable)
     {
       lcr |= UART_LCR_BRK;
@@ -528,6 +529,7 @@ static inline void u16550_enablebreaks(FAR struct u16550_s *priv, bool enable)
     {
       lcr &= ~UART_LCR_BRK;
     }
+
   u16550_serialout(priv, UART_LCR_OFFSET, lcr);
 }