diff --git NuttX/nuttx/arch/arm/src/stm32/stm32_serial.c NuttX/nuttx/arch/arm/src/stm32/stm32_serial.c
index 644c810..b885440 100644
--- NuttX/nuttx/arch/arm/src/stm32/stm32_serial.c
+++ NuttX/nuttx/arch/arm/src/stm32/stm32_serial.c
@@ -1088,10 +1088,10 @@ static inline void up_serialout(struct up_dev_s *priv, int offset, uint32_t valu
 }
 
 /****************************************************************************
- * Name: up_restoreusartint
+ * Name: up_setusartint
  ****************************************************************************/
 
-static void up_restoreusartint(struct up_dev_s *priv, uint16_t ie)
+static inline void up_setusartint(struct up_dev_s *priv, uint16_t ie)
 {
   uint32_t cr;
 
@@ -1113,11 +1113,30 @@ static void up_restoreusartint(struct up_dev_s *priv, uint16_t ie)
 }
 
 /****************************************************************************
+ * Name: up_restoreusartint
+ ****************************************************************************/
+
+static void up_restoreusartint(struct up_dev_s *priv, uint16_t ie)
+{
+  irqstate_t flags;
+
+  flags = enter_critical_section();
+
+  up_setusartint(priv, ie);
+
+  leave_critical_section(flags);
+}
+
+/****************************************************************************
  * Name: up_disableusartint
  ****************************************************************************/
 
-static inline void up_disableusartint(struct up_dev_s *priv, uint16_t *ie)
+static void up_disableusartint(struct up_dev_s *priv, uint16_t *ie)
 {
+  irqstate_t flags;
+
+  flags = enter_critical_section();
+
   if (ie)
     {
       uint32_t cr1;
@@ -1154,7 +1173,9 @@ static inline void up_disableusartint(struct up_dev_s *priv, uint16_t *ie)
 
   /* Disable all interrupts */
 
-  up_restoreusartint(priv, 0);
+  up_setusartint(priv, 0);
+
+  leave_critical_section(flags);
 }
 
 /****************************************************************************
diff --git NuttX/nuttx/arch/arm/src/stm32f7/stm32_serial.c NuttX/nuttx/arch/arm/src/stm32f7/stm32_serial.c
index 1f5445a..faae72a 100644
--- NuttX/nuttx/arch/arm/src/stm32f7/stm32_serial.c
+++ NuttX/nuttx/arch/arm/src/stm32f7/stm32_serial.c
@@ -1070,10 +1070,10 @@ static inline void up_serialout(struct up_dev_s *priv, int offset, uint32_t valu
 }
 
 /****************************************************************************
- * Name: up_restoreusartint
+ * Name: up_setusartint
  ****************************************************************************/
 
-static void up_restoreusartint(struct up_dev_s *priv, uint16_t ie)
+static inline void up_setusartint(struct up_dev_s *priv, uint16_t ie)
 {
   uint32_t cr;
 
@@ -1095,11 +1095,30 @@ static void up_restoreusartint(struct up_dev_s *priv, uint16_t ie)
 }
 
 /****************************************************************************
+ * Name: up_restoreusartint
+ ****************************************************************************/
+
+static void up_restoreusartint(struct up_dev_s *priv, uint16_t ie)
+{
+  irqstate_t flags;
+
+  flags = enter_critical_section();
+
+  up_setusartint(priv, ie);
+
+  leave_critical_section(flags);
+}
+
+/****************************************************************************
  * Name: up_disableusartint
  ****************************************************************************/
 
-static inline void up_disableusartint(struct up_dev_s *priv, uint16_t *ie)
+static void up_disableusartint(struct up_dev_s *priv, uint16_t *ie)
 {
+  irqstate_t flags;
+
+  flags = enter_critical_section();
+
   if (ie)
     {
       uint32_t cr1;
@@ -1136,7 +1155,9 @@ static inline void up_disableusartint(struct up_dev_s *priv, uint16_t *ie)
 
   /* Disable all interrupts */
 
-  up_restoreusartint(priv, 0);
+  up_setusartint(priv, 0);
+
+  leave_critical_section(flags);
 }
 
 /****************************************************************************
@@ -2928,6 +2949,7 @@ int up_putc(int ch)
 
   up_lowputc(ch);
   up_restoreusartint(priv, ie);
+
 #endif
   return ch;
 }
diff --git NuttX/nuttx/arch/arm/src/stm32l4/stm32l4_serial.c NuttX/nuttx/arch/arm/src/stm32l4/stm32l4_serial.c
index dfef76a..8f1fa77 100644
--- NuttX/nuttx/arch/arm/src/stm32l4/stm32l4_serial.c
+++ NuttX/nuttx/arch/arm/src/stm32l4/stm32l4_serial.c
@@ -783,11 +783,11 @@ static inline void stm32l4serial_putreg(FAR struct stm32l4_serial_s *priv,
 }
 
 /****************************************************************************
- * Name: stm32l4serial_restoreusartint
+ * Name: stm32l4serial_setusartint
  ****************************************************************************/
 
-static void stm32l4serial_restoreusartint(FAR struct stm32l4_serial_s *priv,
-                                          uint16_t ie)
+static inline void stm32l4serial_setusartint(FAR struct stm32l4_serial_s *priv,
+                                             uint16_t ie)
 {
   uint32_t cr;
 
@@ -809,12 +809,32 @@ static void stm32l4serial_restoreusartint(FAR struct stm32l4_serial_s *priv,
 }
 
 /****************************************************************************
+ * Name: up_restoreusartint
+ ****************************************************************************/
+
+static void stm32l4serial_restoreusartint(FAR struct stm32l4_serial_s *priv,
+                                          uint16_t ie)
+{
+  irqstate_t flags;
+
+  flags = enter_critical_section();
+
+  stm32l4serial_setusartint(priv, ie);
+
+  leave_critical_section(flags);
+}
+
+/****************************************************************************
  * Name: stm32l4serial_disableusartint
  ****************************************************************************/
 
-static inline void stm32l4serial_disableusartint(FAR struct stm32l4_serial_s *priv,
-                                                 FAR uint16_t *ie)
+static void stm32l4serial_disableusartint(FAR struct stm32l4_serial_s *priv,
+                                          FAR uint16_t *ie)
 {
+  irqstate_t flags;
+
+  flags = enter_critical_section();
+
   if (ie)
     {
       uint32_t cr1;
@@ -851,7 +871,9 @@ static inline void stm32l4serial_disableusartint(FAR struct stm32l4_serial_s *pr
 
   /* Disable all interrupts */
 
-  stm32l4serial_restoreusartint(priv, 0);
+  stm32l4serial_setusartint(priv, 0);
+
+  leave_critical_section(flags);
 }
 
 /****************************************************************************