Fix buffer overwrite while DMA is not completed

Core/Src/canlog.c

@@ -49,19 +49,11 @@ void CAN_Logger_Init(CAN_HandleTypeDef *hcan1, CAN_HandleTypeDef *hcan2)
     filter.FilterActivation = ENABLE;
     filter.SlaveStartFilterBank = 14;
 
-    HAL_NVIC_SetPriority(CAN1_RX0_IRQn, 6, 0);
-    HAL_NVIC_EnableIRQ(CAN1_RX0_IRQn);
-
-    HAL_NVIC_SetPriority(CAN2_RX0_IRQn, 6, 0);
-    HAL_NVIC_EnableIRQ(CAN2_RX0_IRQn);
-
     filter.FilterBank = 0;
     if (HAL_CAN_ConfigFilter(hcan1, &filter) != HAL_OK) Error_Handler();
-    if (HAL_CAN_Start(hcan1) != HAL_OK) Error_Handler();
 
     filter.FilterBank = 14;
     if (HAL_CAN_ConfigFilter(hcan2, &filter) != HAL_OK) Error_Handler();
-    if (HAL_CAN_Start(hcan2) != HAL_OK) Error_Handler();
 }
 /* END CAN_Logger_Init */
 
@@ -120,8 +112,13 @@ void vCANListener(void *argument)
   osMessageQueueId_t queue = (hcan->Instance == CAN1) ? xCAN1RxQueue : xCAN2RxQueue;
   CanMessage_t message;
 
+  if (HAL_CAN_Start(hcan) != HAL_OK) Error_Handler();
   HAL_CAN_ActivateNotification(hcan, CAN_IT_RX_FIFO0_MSG_PENDING);
 
+  uint32_t irqn = (hcan->Instance == CAN1) ? CAN1_RX0_IRQn : CAN2_RX0_IRQn;
+  HAL_NVIC_SetPriority(irqn, 6, 0);
+  HAL_NVIC_EnableIRQ(irqn);
+
   for (;;)
   {
     if (osMessageQueueGet(queue, &message, NULL, osWaitForever) == osOK)

Core/Src/cansend.c

@@ -101,23 +101,27 @@ void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart)
   */
 void vUARTLogger(void *argument)
 {
-    CanMessage_t message;
-    char tx_buffer[45];
+  CanMessage_t message;
+  char tx_buffer[45];
 
-    for (;;)
+  for (;;)
+  {
+    DEBUG_PRINT("Waiting for CAN traffic...\r\n");
+    if (osMessageQueueGet(xUARTQueue, &message, NULL, osWaitForever) == osOK)
     {
-      DEBUG_PRINT("Waiting for CAN traffic...\r\n");
-      if (osMessageQueueGet(xUARTQueue, &message, NULL, osWaitForever) == osOK)
+      osSemaphoreAcquire(xUARTDMASemaphore, osWaitForever);
+      int len = format_can_message(tx_buffer, message.source, &message);
+
+      if (HAL_UART_Transmit_DMA(&huart1, (uint8_t*)tx_buffer, len) == HAL_OK)
       {
-        DEBUG_PRINT("CAN frame detected\r\n");
-        int len = format_can_message(tx_buffer, message.source, &message);
-        if (HAL_UART_Transmit_DMA(&huart1, (uint8_t*)tx_buffer, len) == HAL_OK)
-        {
-            osSemaphoreAcquire(xUARTDMASemaphore, osWaitForever);
-            DEBUG_PRINT("CAN frame sent via UART\r\n");
-        }
-        else DEBUG_PRINT("HAL error, CAN frame NOT sent!\r\n");
+          DEBUG_PRINT("CAN frame sent via UART\r\n");
+      }
+      else
+      {
+        osSemaphoreRelease(xUARTDMASemaphore);
+        DEBUG_PRINT("HAL error, CAN frame NOT sent!\r\n");
       }
     }
+  }
 }
 /* END vUARTLoggerListen */

Core/Src/main.c

@@ -176,7 +176,7 @@ int main(void)
   /* USER CODE END RTOS_MUTEX */
 
   /* USER CODE BEGIN RTOS_SEMAPHORES */
-  xUARTDMASemaphore = osSemaphoreNew(1, 0, NULL);
+  xUARTDMASemaphore = osSemaphoreNew(1, 1, NULL);
   if (xUARTDMASemaphore == NULL) Error_Handler();
   /* USER CODE END RTOS_SEMAPHORES */