Merge pull request #11938 from LMESTM/stm32_serial_clear_rxne

STM32: Update and align serial_clear implementations

Author: 0xc0170

targets/TARGET_STM/TARGET_STM32F0/serial_device.c

@@ -281,8 +281,9 @@ void serial_clear(serial_t *obj)
     struct serial_s *obj_s = SERIAL_S(obj);
     UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
 
-    huart->TxXferCount = 0;
-    huart->RxXferCount = 0;
+    /* Clear RXNE and error flags */
+    volatile uint32_t tmpval __attribute__((unused)) = huart->Instance->RDR;
+    HAL_UART_ErrorCallback(huart);
 }
 
 void serial_break_set(serial_t *obj)

targets/TARGET_STM/TARGET_STM32F1/serial_device.c

@@ -196,8 +196,9 @@ void serial_clear(serial_t *obj)
     struct serial_s *obj_s = SERIAL_S(obj);
     UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
 
-    huart->TxXferCount = 0;
-    huart->RxXferCount = 0;
+    /* Clear RXNE and error flags */
+    volatile uint32_t tmpval __attribute__((unused)) = huart->Instance->DR;
+    HAL_UART_ErrorCallback(huart);
 }
 
 void serial_break_set(serial_t *obj)
@@ -576,7 +577,7 @@ void serial_rx_abort_asynch(serial_t *obj)
 
     // clear flags
     __HAL_UART_CLEAR_FLAG(huart, UART_FLAG_RXNE);
-    volatile uint32_t tmpval __attribute__((unused)) = huart->Instance->DR; // Clear errors flag
+    volatile uint32_t tmpval __attribute__((unused)) = huart->Instance->DR; // Clear Rx empty flag
 
     // reset states
     huart->RxXferCount = 0;

targets/TARGET_STM/TARGET_STM32F2/serial_device.c

@@ -253,8 +253,9 @@ void serial_clear(serial_t *obj)
     struct serial_s *obj_s = SERIAL_S(obj);
     UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
 
-    huart->TxXferCount = 0;
-    huart->RxXferCount = 0;
+    /* Clear RXNE and error flags */
+    volatile uint32_t tmpval __attribute__((unused)) = huart->Instance->DR; 
+    HAL_UART_ErrorCallback(huart);
 }
 
 void serial_break_set(serial_t *obj)
@@ -659,7 +660,7 @@ void serial_rx_abort_asynch(serial_t *obj)
 
     // clear flags
     __HAL_UART_CLEAR_FLAG(huart, UART_FLAG_RXNE);
-    volatile uint32_t tmpval __attribute__((unused)) = huart->Instance->DR; // Clear error flags
+    volatile uint32_t tmpval __attribute__((unused)) = huart->Instance->DR; // Clear Rx empty flags
 
     // reset states
     huart->RxXferCount = 0;

targets/TARGET_STM/TARGET_STM32F3/serial_device.c

@@ -228,7 +228,9 @@ void serial_clear(serial_t *obj)
     struct serial_s *obj_s = SERIAL_S(obj);
     UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
 
-    __HAL_UART_SEND_REQ(huart, UART_RXDATA_FLUSH_REQUEST);
+    /* Clear RXNE and error flags */
+    volatile uint32_t tmpval __attribute__((unused)) = huart->Instance->RDR;
+    HAL_UART_ErrorCallback(huart);
 }
 
 void serial_break_set(serial_t *obj)

targets/TARGET_STM/TARGET_STM32F4/serial_device.c

@@ -289,8 +289,9 @@ void serial_clear(serial_t *obj)
     struct serial_s *obj_s = SERIAL_S(obj);
     UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
 
-    huart->TxXferCount = 0;
-    huart->RxXferCount = 0;
+    /* Clear RXNE and error flags */
+    volatile uint32_t tmpval __attribute__((unused)) = huart->Instance->DR;
+    HAL_UART_ErrorCallback(huart);
 }
 
 void serial_break_set(serial_t *obj)

targets/TARGET_STM/TARGET_STM32F7/serial_device.c

@@ -252,8 +252,9 @@ void serial_clear(serial_t *obj)
     struct serial_s *obj_s = SERIAL_S(obj);
     UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
 
-    __HAL_UART_CLEAR_IT(huart, UART_FLAG_TXE);
-    __HAL_UART_CLEAR_IT(huart, UART_FLAG_RXNE);
+    /* Clear RXNE and error flags */
+    volatile uint32_t tmpval __attribute__((unused)) = huart->Instance->RDR;
+    HAL_UART_ErrorCallback(huart);
 }
 
 void serial_break_set(serial_t *obj)

targets/TARGET_STM/TARGET_STM32H7/serial_device.c

@@ -265,8 +265,9 @@ void serial_clear(serial_t *obj)
     struct serial_s *obj_s = SERIAL_S(obj);
     UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
 
-    __HAL_UART_CLEAR_IT(huart, UART_FLAG_TXE);
-    __HAL_UART_CLEAR_IT(huart, UART_FLAG_RXNE);
+    /* Clear RXNE and error flags */
+    volatile uint32_t tmpval __attribute__((unused)) = huart->Instance->RDR;
+    HAL_UART_ErrorCallback(huart);
 }
 
 void serial_break_set(serial_t *obj)

targets/TARGET_STM/TARGET_STM32L0/serial_device.c

@@ -222,8 +222,9 @@ void serial_clear(serial_t *obj)
     struct serial_s *obj_s = SERIAL_S(obj);
     UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
 
-    huart->TxXferCount = 0;
-    huart->RxXferCount = 0;
+    /* Clear RXNE and error flags */
+    volatile uint32_t tmpval __attribute__((unused)) = huart->Instance->RDR;
+    HAL_UART_ErrorCallback(huart);
 }
 
 void serial_break_set(serial_t *obj)

targets/TARGET_STM/TARGET_STM32L1/serial_device.c

@@ -222,8 +222,9 @@ void serial_clear(serial_t *obj)
     struct serial_s *obj_s = SERIAL_S(obj);
     UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
 
-    huart->TxXferCount = 0;
-    huart->RxXferCount = 0;
+    /* Clear RXNE and error flags */
+    volatile uint32_t tmpval __attribute__((unused)) = huart->Instance->DR;
+    HAL_UART_ErrorCallback(huart);
 }
 
 void serial_break_set(serial_t *obj)

targets/TARGET_STM/TARGET_STM32L4/serial_device.c

@@ -241,8 +241,9 @@ void serial_clear(serial_t *obj)
     struct serial_s *obj_s = SERIAL_S(obj);
     UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
 
-    huart->TxXferCount = 0;
-    huart->RxXferCount = 0;
+    /* Clear RXNE and error flags */
+    volatile uint32_t tmpval __attribute__((unused)) = huart->Instance->RDR;
+    HAL_UART_ErrorCallback(huart);
 }
 
 void serial_break_set(serial_t *obj)