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

Bjorn Helgaas
2026-04-28T22:12:44Z

On Tue, Apr 28, 2026 at 05:02:16PM -0500, Mario Limonciello wrote:
> 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.

It's a fair question. From my perspective I don't think it scales
very well for me to go through all the Sashiko comments and figure out
whether they make sense.

The trivial kernel-doc comment is definitely legit. The others would
take me significant legwork to evaluate.