Re: [PATCH v2 0/6] Improvements to PCI hibernate path

Mario Limonciello
2026-04-28T22:02:18Z

On 4/28/26 16:51, Bjorn Helgaas wrote:
> On Mon, Apr 27, 2026 at 03:50:18PM -0500, Mario Limonciello (AMD) wrote:
>> A few cycles ago I sent out a kernel series for using the S4 paths when
>> the system goes to S5. Some parts of it got merged, and Rafael suggested
>> to split the other parts into smaller pieces across multiple kernel cycles
>> to make bisecting easier.
>
> Thanks for posting this again. Sashiko had a few questions:
> https://sashiko.dev/#/patchset/20260427205024.254677-1-superm1%40kernel.org
>
> I didn't look at them in detail, although I did think the ACPI r6.5
> sec 16.1.5 reference was a little bit obscure. The diagram in sec
> 16.1 certainly implies that wakeups only occur in S1-S4 and not in S5.
>
> Sec 16.1.5 does mention "Remote Start", which is completely undefined
> by the spec but searching does find sec 7.4.2.6, which clearly says
> the system requires a complete boot when awakened. Possibly a little
> misleading to refer to Remote Start as "awakening" when it's
> apparently not a "wakeup".
>
> That section also says "OSPM does not disable wake events
> before setting the SLP_EN bit when entering the S5 system state."

Yeah; especially the comments on patch #2 I'm not in agreement with it.

How exactly do you want to handle the rest of the Sashiko comments? I
suppose one option is to copy and paste them all to refute the ones I
agree or disagree with.

But I was thinking let you and Lukas provide comments and then I'll rev
for your comments (if necessary) and then ones that I agree with
Sashiko, ignore the rest.