Re: [PATCH v2] watchdog: sp5100_tco: Add "action" module parameter

From: rwright
Date: Thu Sep 22 2022 - 13:37:07 EST


On Tue, Sep 20, 2022 at 09:27:21AM +0000, Vladimir Panteleev wrote:
> Allow configuring the "action" bit, as documented in [1].
>
> Previously, the only action supported by this module was to reset the
> system (0). It can now be configured to power off (1) instead.
>
> [1]: https://www.amd.com/system/files/TechDocs/44413.pdf

The referenced AMD document 44413 is over 10 years old, and I'm
concerned when I try to line that document up against the newer versions
that are implemented in AMD's EPYC processors, that the bit being
manipulated as SP5100_WDT_ACTION_RESET is effectively reserved in the
newer references, for example:

https://www.amd.com/system/files/TechDocs/55772-A1-PUB.zip

Is Core::X86::Msr::CpuWdtCfg in the newer document is the same as
WatchDogControl in the cited 44413.pdf? If so, then I would point out
that bit 2 is now included in what is called, CpuWdtTimeBase where
values 2-3H are reserved, meaning bit 2 effectively must be zero.

--
Randy Wright Hewlett Packard Enterprise
Phone: (970) 898-0998 Mail: rwright@xxxxxxx