nrf_libuarte_async TX issue

[linfan68]

Basically, I cannot do continuous TX with nrf_libuarte_async:

Here is simple reproduce:

    static uint8_t text[] = "===TICK===\r\n";
    static uint8_t text_size = sizeof(text);
    static uint8_t text2[] = "+++TOCK+++\r\n";
    static uint8_t text2_size = sizeof(text2);
    while (true)
    {
        err_code = nrf_libuarte_async_tx(&libuarte, text, text_size);
        for (size_t i = 0; i < 1000000; i++)
        {
        }
        err_code = nrf_libuarte_async_tx(&libuarte, text2, text2_size);
        for (size_t i = 0; i < 10000000; i++)
        {
        }
    }

It only output ===TICK=== and no +++TOCK+++

Here is what I've tried:

1. I can confirm that NRF_LIBUARTE_ASYNC_EVT_TX_DONE event has been triggered during the for loop in between

2. If I increase the delay by for loop, both data got through

3. both calls returns 0x00 (SUCCESS)

4. If I put a breakpoint in between, of the NRF_LIBUARTE_ASYNC_EVT_TX_DONE  event, it works

5. I've tried in another project with RTOS and use osDelay to test the gap needed for second transmission, it seems ~300 ms is needed.

help please....

[linfan68]

[Update]

It's not libuarte related, it seems like an EasyDMA issue.

I got another repro without using libuarte, the second message is not showing.

volatile static bool _gotTxDone = false;
void UARTE0_UART0_IRQHandler(void)
{
    if (nrf_uarte_event_check(NRF_UARTE0, NRF_UARTE_EVENT_ENDTX)) {
			nrf_uarte_event_clear(NRF_UARTE0, NRF_UARTE_EVENT_ENDTX);
			_gotTxDone = true;
    }

    return;
}

// ... main...
  uint8_t text[] = "===TICK===\r\n";
  uint8_t text_size = sizeof(text);
  uint8_t text2[] = "+++TOC+++\r\n";
  uint8_t text2_size = sizeof(text2);

  while (true) {
		NRF_LOG_INFO("=========");
		NRF_LOG_FLUSH();

		_gotTxDone = false;
    NRF_UARTE0->TXD.PTR = (uint32_t)text;
    NRF_UARTE0->TXD.MAXCNT = (uint32_t)text_size;
    NRF_UARTE0->TASKS_STARTTX = 1;
    while (!_gotTxDone) {; }

		for (size_t i = 0; i < 100000; i++) { }
		
		_gotTxDone = false;
    NRF_UARTE0->TXD.PTR = (uint32_t)text2;
    NRF_UARTE0->TXD.MAXCNT = (uint32_t)text2_size;
    NRF_UARTE0->TASKS_STARTTX = 1;
    
    
    while (!_gotTxDone) {; }
    NRF_LOG_FLUSH();
		for (size_t i = 0; i < 10000000; i++) { }
  }