linux-kernel - Re: [PATCH v4 1/2] watchdog: Add a new flag WDIOF_STOP

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Message-ID: <7ac2b8db-22c7-4168-b1b7-4f9f0ab10531@pengutronix.de>
Date: Wed, 5 Mar 2025 12:01:53 +0100
From: Ahmad Fatoum <a.fatoum@...gutronix.de>
To: George Cherian <gcherian@...vell.com>,
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 Marek Behún <kabel@...nel.org>,
 Pengutronix Kernel Team <kernel@...gutronix.de>
Subject: Re: [PATCH v4 1/2] watchdog: Add a new flag WDIOF_STOP_MAYSLEEP

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.

Cheers,
Ahmad

> 
>>
>> Marek
> 
> -George


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