[Solved]Problem with Usart Irq

[SDall.11]

Hi at all,

Sometime happens that usart2 irq freeze and HAL_UART_RxCpltCallback isn't called.

From this moment I can send data (I use blocking instruction HAL_UART_Transmit), but don't receive any.

When this happens, HAL_UART_ErrorCallback don't called too.

In this situation, HAL_Receive_IT returns always HAL_BUSY.

I tried to solve calling these instruction when the status is different from HAL_OK:

  __HAL_UART_CLEAR_OREFLAG(huart);

  __HAL_UART_CLEAR_NEFLAG(huart);

  __HAL_UART_CLEAR_FEFLAG(huart);

  __HAL_UART_DISABLE_IT(huart, UART_IT_ERR);

  huart->ErrorCode = HAL_UART_ERROR_NONE;

  Uart2Status = HAL_UART_Receive_IT(huart, (uint8_t *)&ch, 1);

This solution seems to solve for some tries only.

At the moment, when IRQ freeze, to solve the problem, I must to restart device.

The problem is random.

Can you help me?

Thanks.

[Tesla DeLorean]

Break in debugger to understand where it "freeze"

Interrupt Handlers will reenter (tail-chain) continuously if the cause isn't serviced properly.

Have Error_Handler() and HardFault_Handler() output actionable data.

[SDall.11]

Hi clive1 and thanks for answer.

Excuse me, but maybe don't understand your answers.

--> Break in debugger to understand where it "freeze"

I can't break, because my device continue to work fine, with the exception of serial reception.

There isn't a point where software go in loop or similar.

I know only that HAL_Receive_IT returns HAL_BUSY and if I place a breakpoint into HAL_UART_RxCpltCallback this callback doesn't called even though I am receiving data.

About Error_Handler() and HardFault_Handler() I don't understand what you told me :(

Sorry!

[Guenael Cadier]

Dear @SDall.1​ 

If an overrun error is detected, it could prevent further RXNE interrupts to be raised.

Did you implement some specific treatments in the HAL_UART_RxCpltCallback() callback ?

For example, please make sure to not call a long or blocking process in the callback, as the callback is executed within the Interrupt context.

If you execute a Tx operation by calling HAL_UART_Transmit() in HAL_UART_RxCpltCallback(), this means that RX interrupt treatment will last at least longer time than the transmission time. if new characters are received during this time, overrun error might occur ...

Regards

[SDall.11 · Accepted solution]

Hi at all,

I probably solved it.

I had used HAL_UART_Transmit instead of HAL_UART_Transmit_IT.

Now (with HAL_UART_Transmit_IT) it seems to work fine.

Thanks at all for help.