'POWER_CLOCK_IRQHandler' gets called after ~100seconds under unknown circumstances (causes the product to freeze)

RE: 'POWER_CLOCK_IRQHandler' gets called after ~100seconds under unknown circumstances (causes the product to freeze)

Vidar Berg — Thu, 23 Sep 2021 11:58:28 GMT

koniho, I don't know what's causing this strange behaviour for OP, all I know is that it appears to be related to the LFXO. I suggest you create a new ticket if you are experiencing a similiar issue.

RE: 'POWER_CLOCK_IRQHandler' gets called after ~100seconds under unknown circumstances (causes the product to freeze)

koniho — Wed, 22 Sep 2021 18:59:50 GMT

Is it possible that this condition could occur with the softdevice enabled (using HFCLK and external LFCLK)

RE: 'POWER_CLOCK_IRQHandler' gets called after ~100seconds under unknown circumstances (causes the product to freeze)

Vidar Berg — Tue, 14 Sep 2021 07:11:56 GMT

Glad to hear that it worked. But please note that the Synthesized clock source is generally not recommend because it may increase the idle current (it forces the HF clock to always be on like UART does).

I'm still not sure why the LFXO is behaving strangely. Have you changed load caps or the 32K crystal recently?

RE: 'POWER_CLOCK_IRQHandler' gets called after ~100seconds under unknown circumstances (causes the product to freeze)

Mircea Coman — Mon, 13 Sep 2021 13:48:11 GMT

Vidar, it worked! Changing Clock source to Synth caused the 'POWER_CLOCK_IRQHandler' to be always called right after device started and the CLOCK did not stop since (wirking as expected).

What I also discovered is that if I enable the SoftDevice by default, the CLOCK also doesn't stop, even if I leave the Clock source to '1' in 'sdk_config.h'.

Thank you!

RE: 'POWER_CLOCK_IRQHandler' gets called after ~100seconds under unknown circumstances (causes the product to freeze)

Vidar Berg — Fri, 10 Sep 2021 15:35:06 GMT

[quote userid="107254" url="~/f/nordic-q-a/79488/power_clock_irqhandler-gets-called-after-100seconds-under-unknown-circumstances-causes-the-product-to-freeze/329073#329073"]What are the conditions under which CLOCK can be stopped intarnally?[/quote]

That should never happen. The application should be in complete control of when the LFCLK is on or off. And most applications tend to keep it always on.

[quote userid="107254" url="~/f/nordic-q-a/79488/power_clock_irqhandler-gets-called-after-100seconds-under-unknown-circumstances-causes-the-product-to-freeze/329072#329072"]I tried running the code on an development board (instead of the production board) and 'POWER_CLOCK_IRQHandler' is called right at the beginning of device execution...[/quote]

Interesting.. So what clock source are you using on your board? Have you tried with a different source? E.g. sdk_config.h::CLOCK_CONFIG_LF_SRC 2 /*Synth */

RE: 'POWER_CLOCK_IRQHandler' gets called after ~100seconds under unknown circumstances (causes the product to freeze)

Mircea Coman — Fri, 10 Sep 2021 15:26:23 GMT

What are the conditions under which CLOCK can be stopped intarnally? Is it even possible that the RTC counter is not incredemented anymore, timer callback not called and still, 'nrf_drv_clock_lfclk_is_running()' returns true ?

RE: 'POWER_CLOCK_IRQHandler' gets called after ~100seconds under unknown circumstances (causes the product to freeze)

Mircea Coman — Fri, 10 Sep 2021 15:05:10 GMT

VIdar, thank you for your answers.

1. 3. Strangely, the event received in POWER_CLOCK_IRQHandler is 'NRF_CLOCK_EVENT_LFCLKSTARTED' , which, by reading the code in 'nrf_drv_clock.c' it should start the LFCLK, instead of stopping it. This is 140 seconds after the device started, and all the while Timer Interrupt was called correctly.

After the call to 'POWER_CLOCK_IRQHandler', the timer callback is not called anymore and 'NRF_RTC1->COUNTER' is no more incremented.

I enabled LOGGING in CLOCK, UART, GPIO but there's no message indicating what is happening.

My recent assumption was that the device was entering low power mode, and I tried setting the mode to 'Constant Latency Mode' by caling 'nrf_power_task_trigger(NRF_POWER_TASK_CONSTLAT);'. Did not help.

2. The values for POWER and CLOCK (at startup, read in main()):

- NRF_POWER->INTENSET == 2 (?);

- NRF_CLOCK->INTENSET == 2 (LFCLKSTARTED?)

In 'POWER_CLOCK_IRQHandler' the values of the 2 registers is zero.

BTW, The clock is initialized in main() by calling 'nrf_drv_clock_init()'

I tried running the code on an development board (instead of the production board) and 'POWER_CLOCK_IRQHandler' is called right at the beginning of device execution...

Ideas?

RE: 'POWER_CLOCK_IRQHandler' gets called after ~100seconds under unknown circumstances (causes the product to freeze)

Vidar Berg — Fri, 10 Sep 2021 13:21:21 GMT

I see, thanks for confirming. It's hard for me to say what causes POWER_CLOCK_IRQn to be raised and whether it should be expected or not as the trigger source can be any interrupt enabled event in POWER or CLOCK.

Some more follow up questions:

1. Is the problem caused by the program not returning from POWER_CLOCK_IRQHandler(), or does it return, but without the LF clock running?

2. Which interrupts do you have enabled in POWER->INTENSET and CLOCK->INTENSET?

3. Can you read which event signal have been set when you are in the POWER_CLOCK_IRQHandler?

Thanks,

Vidar

RE: 'POWER_CLOCK_IRQHandler' gets called after ~100seconds under unknown circumstances (causes the product to freeze)

Mircea Coman — Fri, 10 Sep 2021 11:18:07 GMT

We use SEGGER | SDK 12.3.0 | SoftDevice is disabled | WDT is disabled

The bug is reproducible even if SD + WDT are enabled (as they are in the production). This bug went unnoticed for years while tousands of devices were / are running in the field.

Could you tell me why 'POWER_CLOCK_IRQHandler' is called? Looks like device enters power saving mode for some (unknown) reason?

RE: 'POWER_CLOCK_IRQHandler' gets called after ~100seconds under unknown circumstances (causes the product to freeze)

Vidar Berg — Fri, 10 Sep 2021 11:11:03 GMT

Hello,

Are you enabling the watchdog timer in your application, and in that case, is there a chance that you may have experienced a WD reset? If so, please check if you may be impacted by this bug mentioned here:

https://devzone.nordicsemi.com/f/nordic-q-a/65422/what-are-sdk-17-x-0-known-issues

RE: 'POWER_CLOCK_IRQHandler' gets called after ~100seconds under unknown circumstances (causes the product to freeze)

Mircea Coman — Thu, 09 Sep 2021 16:17:06 GMT

Our issue seems to be similar to : https://devzone.nordicsemi.com/f/nordic-q-a/68666/app-timer-stops-working---need-a-power-cycle-to-fix-issue

I reached the author of the above ticket and he did not found the cause so far.