Is it possible to set BLE and FDS's interrupt priorities separately?

RE: Is it possible to set BLE and FDS's interrupt priorities separately?

Susheel Nuguru — Thu, 05 Aug 2021 06:34:23 GMT

what you are trying to do in the pseudocode and the main discussion of the thread seems to have diverged.

I thought that the discussion of this thread is about priorities in how BLE and FDS events are handled and not the priority of new FDS procedure request.

RE: Is it possible to set BLE and FDS's interrupt priorities separately?

RJ Fang — Thu, 05 Aug 2021 00:32:24 GMT

I have tried that but it didn't solve my issue. So specifically I am trying to call fds_write inside a ble interrupt handler:

on_write(data from ble)

{

fds_write(data from ble);

}

The on_write() function is the handler for ble writing event. If I chagned the priority like you said, will this function working theoretically?

RE: Is it possible to set BLE and FDS's interrupt priorities separately?

Susheel Nuguru — Wed, 04 Aug 2021 13:54:09 GMT

change NRF_SDH_SOC_STACK_OBSERVER_PRIO from 0 to 1 if you think that fstorage events should be pulled first from the item queue even if ble event arrived first.

RE: Is it possible to set BLE and FDS's interrupt priorities separately?

RJ Fang — Wed, 04 Aug 2021 12:46:07 GMT

Hi Susheel,

Thanks for your reply! Could you please specify what should I do if I want to set FDS's interrupt priority higher then BLE's priority?

RE: Is it possible to set BLE and FDS's interrupt priorities separately?

Susheel Nuguru — Tue, 03 Aug 2021 12:15:46 GMT

Hi Fang,

FDS uses fstorage.

Inside nrf_fstorage_sd.c you can see that it uses SDH observer priority of 0.

NRF_SDH_SOC_OBSERVER(m_sys_obs, 0, nrf_fstorage_sys_evt_handler, NULL);

and in the SDK config you can see that NRF_SDH_SOC_STACK_OBSERVER_PRIO is also set to 0. These are software priorities based on the same interrupt line SWI2_IRQn that are used by softdevice to notify both BLE/ANT and also fstorage events.

These events are queued inside softdevice and these software priorities only define the order in which the handlers for these events are called. In your case, the BLE events and Fstorage events are of same priority, so if BLE events comes first in the queue they are processed first and if fstorage events comes first in the queue, they are processed first delaying the BLE event processing. If you want to change this behavior, you need to change the priorities of these as to how you want priority preference between BLE and fstorage events.