nRF9160 UART RX stoped

[Siyou]

Hi,

When we do the UART stress testing with serial_lte_modem sample, the slm will crash by sending AT commands with interval 100ms.

the debug log will show "<wrn> at_host: RX_STOPPED" and the RX_stop reason is UART_ERROR_FRAMING(4), after this event occurred, the UART RX will be no longer available, that means the host cannot communicate with nRF9160 anymore.

How to recover the UART RX in this condition? I tried below functions but still failed.

        err = uart_callback_set(uart_dev, uart_callback, NULL);
		buf_num = 1U;
		err = uart_rx_enable(uart_dev, &uart_rx_buf[0], 1, K_FOREVER);

[Håkon Alseth]

Hi,

 

Are you trying to re-enable RXD in the callback where you get the error, or is this after the uart callback has finished?

Due to ordering of execution in the uart driver: https://github.com/nrfconnect/sdk-zephyr/blob/master/drivers/serial/uart_nrfx_uarte.c#L726-L727

The _rx_disable() will be called after you have been notified in the application.

 

PS: I have reported this internally, as the driver shall not make assumptions on how the application shall handle an error situation.

 

Kind regards,

Håkon