unexpected SWI during softdevice startup

RE: unexpected SWI during softdevice startup

nevi — Mon, 22 Mar 2021 16:31:19 GMT

I use a merged firmware that contains the app + bootloader + bootloader settings page + soft device.

Maybe it happens only after I flash this signed, merged firmware with nrfutil. After this flashing, the first boot (or at least by the time the firmware app starts) is unusually slow (3-4 seconds).

I think the error does not occur after the consequent boots.

So maybe the bootloader cause the error at the first run, but why?

RE: unexpected SWI during softdevice startup

nevi — Mon, 22 Mar 2021 16:03:16 GMT

Hi,

I also experienced this error on my custom board with nrf52832, sdk16.

The stack trace:

Thread [1] (Suspended: Breakpoint hit.)	
	11 app_error_handler() app_error_handler_gcc.c:49 0x0003ef46	
	10 assert_nrf_callback() b_le.c:226 0x0002add0	
	9 vTaskNotifyGiveFromISR() tasks.c:4796 0x00038642	
	8 SWI2_EGU2_IRQHandler() nrf_sdh_freertos.c:35 0x0005258c	
	7 <signal handler called>()  0xfffffff9	
	6 memset()  0x00052c7a	
	5 prvInitialiseNewTask() tasks.c:853 0x00036f3e	
	4 xTaskCreate() tasks.c:808 0x00036f02	
	3 nrf_sdh_freertos_init() nrf_sdh_freertos.c:68 0x00052640	
	2 bleInit() b_le.c:2793 0x0002e75c	
	1 main() main.c:210 0x00026606

It is occured on the first power on reset, but not after software reset (NVIC_SystemReset()).

I also noticed that maybe the error doesn't appear after every compiling.

Did anyone figure out the cause of the error?

RE: unexpected SWI during softdevice startup

Susheel Nuguru — Thu, 30 Nov 2017 20:16:53 GMT

Hi Terry, did you solve this issue? if so, please update this thread.

RE: unexpected SWI during softdevice startup

Susheel Nuguru — Wed, 22 Nov 2017 09:16:43 GMT

please help me reproduce this problem on a DK. I will debug this and give you a workaround if possible.

RE: unexpected SWI during softdevice startup

Terry — Fri, 17 Nov 2017 16:28:10 GMT

This change did not fix the problem. Still dies after SWI at tasks.c line 4309: xTaskToNotify is 0.

	Thread #1 57005 (Suspended : Signal : SIGTRAP:Trace/breakpoint trap)	
		vTaskNotifyGiveFromISR() at tasks.c:4,309 0x264de	
		SWI2_EGU2_IRQHandler() at nrf_sdh_freertos.c:65 0x282d0	
		<signal handler called>() at 0xfffffff9	
		memset() at 0x39d44	
		prvAllocateTCBAndStack() at tasks.c:3,136 0x2611e	
		xTaskGenericCreate() at tasks.c:562 0x2555e	
		nrf_sdh_freertos_init() at nrf_sdh_freertos.c:98 0x28352	
		ble_init() at task_ble.c:128 0x23b92	
		main() at main.c:63 0x39a0e

RE: unexpected SWI during softdevice startup

Susheel Nuguru — Thu, 16 Nov 2017 11:39:06 GMT

We found a bug that we fixed in SDK14.1

Please replace the function

/* This function gets events from the SoftDevice and processes them. */
static void softdevice_task(void * pvParameter)
{
    NRF_LOG_DEBUG("Enter softdevice_task.");

    if (m_task_hook != NULL)
    {
        m_task_hook(pvParameter);
    }

    while (true)
    {
        (void) ulTaskNotifyTake(pdTRUE,         /* Clear the notification value before exiting (equivalent to the binary semaphore). */
                                portMAX_DELAY); /* Block indefinitely (INCLUDE_vTaskSuspend has to be enabled).*/
        nrf_sdh_evts_poll();
    }
}

/* This function gets events from the SoftDevice and processes them. */
static void softdevice_task(void * pvParameter)
{
    NRF_LOG_DEBUG("Enter softdevice_task.");

    if (m_task_hook != NULL)
    {
        m_task_hook(pvParameter);
    }

    while (true)
    {
        nrf_sdh_evts_poll();

        (void) ulTaskNotifyTake(pdTRUE,         /* Clear the notification value before exiting (equivalent to the binary semaphore). */
                                portMAX_DELAY); /* Block indefinitely (INCLUDE_vTaskSuspend has to be enabled).*/
    }
}

There was a deadlock in the way we locked ourself in the ulTaskNotify. Now we will first poll for the events that already happened before the softdevice_task was created before suspending.