Re: [PATCH 7/10 v2] Generic Watchdog Timer Driver

[Mark Lord <kernel@teksavvy.com>]

On 11-06-22 04:13 PM, Wim Van Sebroeck wrote:
> Hi Mark,
> 
>>>>> Then you'd need an additional interface to specify which watchdog as soon
>>>>> as we support multiple watchdogs.
>>>>
>>>> You can always have multiple ways of setting nowayout -- hardware requirements,
>>>> global module option, local module option, and a new ioctl command -- but
>>>> what is being used is then the logical OR of all of them.
>>>
>>> An ioctl for it would make a lot of sense as watchdogs are often compiled
>>> in so currently there isn't a good way to runtime set this.
>>
>> I wouldn't mind a kernel parameter to enable a hardware watchdog timer at boot.
>> Currently, there's a window at startup where the watchdog is not enabled,
>> and the system could lock up and die in there without it being triggered.
> 
> This is another tricky thing were developers will always discuss about.
> What you don't want to happen is that the watchdog reboots your system when it does
> an fsck at bootup (for instance because the system rebooted by the watchdog and left
> the filesystem in a dirty state...).
> 
> So it's more complex if you look at the overal system...

Sure, but that's got little to do with wanting a kernel parameter to OPTIONALLY
enable a hardware watchdog timer at boot.

Filesystem checks are a separate issue, easily worked around in practice.