Watchdog isn't disabled at boot when CONFIG_WDT_DISABLE_AT_BOOT=y

[douglas.malnati]

Windows 11, WSL2, NCS 2, VSCode

I want to be able to reboot my chip without the watchdog automatically being enabled on boot.

I cannot seem to disable it through the API (-PERM return value).

This happens when I  sys_reboot(SYS_REBOOT_COLD) or NVIC_SystemReset().

My prj.conf has:

CONFIG_WATCHDOG=y

CONFIG_NRFX_WDT0=y

CONFIG_WDT_DISABLE_AT_BOOT=y

Is there something I'm misunderstanding?

How can I get this to work?

Thanks.

[douglas.malnati]

Thanks Sigurd, that's a last-ditch approach for sure.  I'm surprised this is such a troublesome peripheral.

Can you help me understand part of the spec meaning?

This talks about starting "running again" - after a watchdog reset also?  What is the meaning of being able to configure those registers at that time?  Doesn't this mean you can set up the watchdog on startup?

Thanks.

[Sigurd Hellesvik]

Some reset-causes for the nRF will also reset the WDT peripheral. See the table below:

If the WDT is reset, you will have to manually start it again.
So, you can disable the WDT by resetting the nRF Chip in either of these ways.

Side note: The WDT peripheral in our nRF5340 has functionality for stopping the watchdog.

Regards,
Sigurd Hellesvik

[Sigurd Hellesvik]

https://github.com/zephyrproject-rtos/zephyr/pull/73091