Service event handler: IRQ callback or FreeRTOS task?

RE: Service event handler: IRQ callback or FreeRTOS task?

CheMax — Mon, 10 Sep 2018 06:44:22 GMT

My question was not connected with the periphery, but with callback functions for services. this is essentially part of the stack. And in my case, I do not use the library from NRF to work with peripherals. so I can not say exactly how it will be with interrupts.

I independently fully configure and control the periphery, including enabling and describing the interrupt vector. in this case I am forced to use the function _FromISR.

I can assume that the callback functions you describe are not called in the context of the operating system. and therefore it is necessary to use the suffix _FromISR.

RE: Service event handler: IRQ callback or FreeRTOS task?

secondbest — Sat, 08 Sep 2018 23:12:25 GMT

Hi eyalasko ;

Can you find any answer about this question? I got error during freertos and spi?

Thanks.

RE: Service event handler: IRQ callback or FreeRTOS task?

eyalasko — Mon, 03 Sep 2018 09:21:02 GMT

Hello Aryan,

I'm facing the same questions as CheMax - Do all interrupts captured by the softdevice and serviced by the application in the event handlers in a (freertos) task context ?

Specifically I would like to verify that:

GPIO interrupts - serviced in freertos task context in a callback registered by nrf_drv_gpiote_in_init() ?
UART interrupts - serviced in freertos task context in a callback registered by NRF_SERIAL_CONFIG_DEF() macro ?
TWI interrupts - serviced in freertos task context in a callback registered in nrf_drv_twi_init() ?
SPI interrupt - serviced in freertos task context in a callback registered by NRF_SPI_MNGR_TRANSACTION_SET_DEFAULT() macro ?

If this is indeed the case, in what scenario will callback run in a 'true' interrupt context (ISR)with/without softdevice. On what conditions should I use freertos' _fromISR() api ?

Many thanks in advance

RE: Service event handler: IRQ callback or FreeRTOS task?

CheMax — Mon, 16 Jul 2018 05:55:22 GMT

Many thanks, Aryan.

In the near future, I may have new questions))).

best regards,

Max

RE: Service event handler: IRQ callback or FreeRTOS task?

Susheel Nuguru — Sun, 15 Jul 2018 19:38:14 GMT

No, the event handler itself is not called from ISR context, it is called from the task context so you do not need FromISR postfix.

RE: Service event handler: IRQ callback or FreeRTOS task?

CheMax — Sat, 14 Jul 2018 08:08:01 GMT

Thank Aryan,

I understand that if I want to pass the event of enabling a notification for this service to the task I need, I should use the api function for interrupts (with a suffix FromIsr).

For example, this:

static void ads_cds_evt(cds_svc_t *cds_service, cds_svc_evt_t *p_evt)
{
  NRF_LOG_INFO("Incoming event: %d", p_evt->evt_type);
  switch(p_evt->evt_type)
  {
    case CDS_SVC_EVT_NOTIFICATION_ENABLED: 
     xEventGroupSetBitsFromISR(eAdsFlags, eAdsEvtNtfEnable, NULL);
    break;
    
    ...
  }
}

Is not it?

RE: Service event handler: IRQ callback or FreeRTOS task?

Susheel Nuguru — Fri, 13 Jul 2018 15:53:48 GMT

Very nice questions CheMax,

1) You could have directly handled all the services from this IRQ like a non-RTOS standalone application, then you know, it doesn't look neat to process so much in the interrupts when we can do that better in the RTOS tasks. To answer you question, services are handled in the task.

2) You have pasted the code snippet exactly where this happens. The event handling is done in the task that suspends itself until the SWI interrupt resumes it to process incoming events.