osSemaphoreRelease hangs the MCU?
Hello,
I am having trouble releasing a semaphore on the STM32H745I-DISCO.
The context is as follows: I need to capture a breakline on UART2. When the interrupt triggers, I need to read a character and, depending on the received character, either send characters back or do nothing.
To avoid executing the handling code inside the interrupt, I have placed it inside a task with an osSemaphoreWait. My idea is that when the breakline interrupt occurs, the osSemaphoreRelease line should be executed, releasing the semaphore and running the code that manages UART communication.
main.c
int main(void){
osSemaphoreDef(LIN_breakSem);
LIN_breakSem = osSemaphoreCreate(osSemaphore(LIN_breakSem), 1);
osSemaphoreWait(LIN_breakSem, osWaitForever);//here decrements de counter to 0
osThreadDef(defaultTask, StartDefaultTask, osPriorityNormal, 0, 512);
defaultTaskHandle = osThreadCreate(osThread(defaultTask), NULL);
osThreadDef(LIN_breakTask, LIN_break_fn, osPriorityNormal, 0, 512);
LIN_breakTaskHandle = osThreadCreate(osThread(LIN_breakTask), (void *)LIN_breakSem);
osKernelStart();
while(1){}
}
void LIN_break_fn(void const * argument)
{
while(1){
osSemaphoreId LIN_breakSem = (osSemaphoreId) argument;
vuelve:
if (LIN_breakSem != NULL){
printf("LIN_breakSem = %d\n", LIN_breakSem);
}else{
printf("LIN_breakSem == NULL\n");
osDelay(5000);
goto vuelve;
}
osSemaphoreWait(LIN_breakSem, osWaitForever);
/*Manage the communication*/
osSemaphoreWait(LIN_breakSem, osWaitForever);
}
stm32h7xx_it.c
void USART2_IRQHandler(void)
{
/* USER CODE BEGIN USART2_IRQn 0 */
char flagtmp=0;
USART_TypeDef *U = USART2;
uint32_t isrflags = U->ISR; // status
if (isrflags & USART_ISR_LBDF) {
U->ICR = UART_CLEAR_LBDF;
flagtmp = 1;
}
/* USER CODE END USART2_IRQn 0 */
HAL_UART_IRQHandler(&huart2);
/* USER CODE BEGIN USART2_IRQn 1 */
if(flagtmp){
printf("LIN_breakSemInt = %d\n", LIN_breakSem);
printf("releasing...\n");
//osSemaphoreRelease(LIN_breakSem);
int status = osSemaphoreRelease(LIN_breakSem);
printf("Status = %x\n", status);
flagtmp = 0;
}
/* USER CODE END USART2_IRQn 1 */
}
The problem is that when the osSemaphoreRelease in line 19 is executed inside the interrupt, the microcontroller hangs.
I attach the code: as you can see in the interrupt code after release is printed the status of osSemaphoreRelease but here the MCU hangs and nothing more is printed :')
Any idea?
Thanks.