Re: [PATCH v4 1/2] watchdog: Add a new flag WDIOF_STOP_MAYSLEEP

From: Guenter Roeck
Date: Wed Mar 05 2025 - 18:58:53 EST


On 3/5/25 03:01, Ahmad Fatoum wrote:
Hi George,
Hi Guenter,

On 05.03.25 11:34, George Cherian wrote:
why is armada_37xx_wdt also here?
The stop function in that driver may not sleep.
Marek,

Thanks for reviewing.
Since the stop function has a regmap_write(), I thought it might sleep.
Now that you pointed it out, I assume that it is an MMIO based regmap being used for armada.
I will update the same in the next version

Failure to add WDIOF_STOP_MAYSLEEP when it's needed can lead to
kernel hanging. Failure to add an alternative WDIOF_STOP_ATOMIC
would lead to the kernel option being a no-op.

I think a no-op stop_on_panic (or reset_on_panic) is a saner default.


Agreed. Also, I like WDIOF_STOP_ATOMIC more than the WDIOF_STOP_NOSLEEP
I had suggested in my other response.

Thanks,
Guenter