Re: [PATCH] ACPI: EC: Fix CPU frequency limitation on AMD platforms after suspend/resume

Rafael J. Wysocki
2025-04-28T19:45:40Z

On Mon, Apr 28, 2025 at 9:11 PM Mario Limonciello
<mario.limonciello@amd.com> wrote:
>
> On 4/28/2025 2:02 PM, Rafael J. Wysocki wrote:
> > On Mon, Apr 28, 2025 at 8:23 PM Mario Limonciello
> > <mario.limonciello@amd.com> wrote:
> >>
> >> On 4/28/2025 4:51 AM, Marcus Bergo wrote:
> >>> Yes, it does.
> >>>
> >>
> >> OK thanks for confirming. Considering your finding with this patch
> >> you've shared and knowing there is a timing dependency that delaying the
> >> next s2idle cycle helps I do wonder if we should keep exploring.
> >>
> >> Rafael, do you have thoughts here? Specifically do you think it's worth
> >> revisiting if b5539eb5ee70 was the correct move.
> >
> > Well, it was done for a reason that is explained in its changelog. I
> > think that the problem addressed by it is genuine, isn't it?
> >
> I mean yes - of course. My inquiry was whether this should be the
> default behavior or if it should have been a quirked behavior.

I believe that it should be the default behavior because the EC GPE
needs to be cleared after handling an EC event which effectively is
what the suspend-to-idle code does.

> I don't have a good sense for the rest of the ecosystem what the impacts
> would really be at flipping it. Would it be worth adding a module
> parameter debug knob and survey what happens on a wide variety of machines?

Maybe, if you suspect that this might be a widespread issue.