Lockup with SDK12.3 with FreeRTOS power consumption fix.

[Justin]

I've recently discovered the power consumption issue with FreeRTOS and SDK12.3: devzone.nordicsemi.com/.../

So, I am now using SDK12.3 with SDK13.1 FreeRTOS files.

The power consumption is back to normal, however the modified files are producing a lockup (seen via WDT reset). The WDT reset occurs every few hours, so I haven't been to isolate it in a debugger.
Before making the changes to fix the power consumption, we've had hundreds of devices deployed and functioning properly with no lockups. The only changes have been the new FreeRTOS files.

Any suggestions on what could be causing this issue introduced by the changes to fix the power consumption?

Are there any other configuration (sdk/freeRTOS) changes or updated files I should use?

What is the recommended IRQ priority for the RTC (its the RTOS tick source) when using FreeRTOS and the SoftDevice?

Also, what is the recommended task priority (on the higher or lower end?) for the task which handles SoftDevice events?

nRF52, S132 3.0.0, SDK12.3, FreeRTOS from 1SDK3.1, gcc, eclipse.

**Update:

• i do not experience this lockup/WDT reset when i turn tickless idle OFF. of course, this is not an option for a battery powered device.

• i do not experience this lockup/WDT reset when using the freertos files from SDK 12.1 instead of 13.1, the lockup/WDT reset goes away, but power consumption is worse (~80uA more).

[Dave_couling]

I'm using Priority 6 for my Timer_task priority. Was getting odd behaviour when it was equal or less than other threads including BLE.

[Justin]

i've removed NRF LOG (RTT) and some nrf interrupts so that the only active IRQs are RTC and the WDT (and softdevice activity). the lockup still persists. so it would seem to be freertos (/config) or softdevice related.

[Dave_couling]

I was able to capture one of the ASSERT in tasks.c related to this line of code" configASSERT( ( xTickCount + xTicksToJump ) <= xNextTaskUnblockTime );

I think this is a bug in the freeRTOS source files

[Dave_couling]

Are you manually Suspending/Resuming Threads to save power?

[Justin]

the task which handles softdevice events blocks on a semaphore given in the ble event handler. all other RTOS tasks just block on queues waiting for things to do.