Re: [11/12] watchdog: sp5100-tco: Abort if watchdog is disabled by hardware

From: Guenter Roeck
Date: Tue Jan 09 2018 - 18:37:12 EST


Hi,

On Tue, Jan 09, 2018 at 05:58:07PM -0500, Lyude Paul wrote:
> Hi! I'm the one from the Fedora bugzilla who said they'd help review these
> patches. I might end up responding to this with a real review comment after
> this message, but first:
>
> mind cc'ing me future versions of this patchset and also, is there any way you

Sure.

> know of that one could figure out whether or not the sp5100_tco wdt is
> actually disabled by the OEM on a board? I tried testing these patches with my

That is what the code is trying to do today.

> system and it appears to be convinced that it's disabled on my system, but I'm
> hoping something in this patch is just brokenâ
>

I tested the driver on three different boards. MSI B350M MORTAR,
MSI B350 TOMAHAWK, and Gigabyte AB350M-Gaming 3. CPU is Ryzen 1700X
on all boards.

On the MSI boards, the watchdog is reported as disabled. Enabling it
and letting it expire does not have an effect. I am using the Super-IO
watchdog instead on those boards (and it works).

On the Gigabyte board, the watchdog is reported as enabled, and it works
(and the watchdog on the Super-IO chips does not work).

Feel free to play with the driver. Maybe there is a means to enable the
watchdog if it is disabled. Unfortunately, I was unable to figure out how
to do it, so I thought it is better to report the fact and not instantiate
the watchdog if it doesn't work.

Hope this helps,
Guenter