-----Original Message-----
From: Jérôme de Bretagne [mailto:jerome.debretagne@gmail.com]
Sent: Friday, June 9, 2017 6:11 PM
To: Limonciello, Mario <redacted>
Cc: ACPI Devel Maling List <redacted>; Linux PM <linux-
pm@vger.kernel.org>; Rafael J. Wysocki [off-list ref]; Andy Shevchenko
[off-list ref]; Darren Hart [off-list ref];
Srinivas Pandruvada [off-list ref]; Mika Westerberg
[off-list ref]
Subject: Re: [PATCH 0/3] ACPI / sleep: Support power button wakeup from S2I on
recent Dell laptops

quoted

I got a response back that confirmed that this machine only is supported
with CS/MS.  I would not expect S3 to work properly.

Thanks for the confirmation, that's what I expected following the feedback on
other recent Dell machines.

Specifically the Dell machines that aren't sold with Linux.  The machines sold
with Linux do undergo S3 testing and BIOS issues are sorted out for S3.

Those it makes sense to leave S3 in the BIOS until S2I is working well on Linux
at least.

quoted

Even if S3 is part of the ACPI namespace, the behavior that Windows follows
is that S3 is not offered when the low power idle bit is set in FADT.

I know that the current behavior in Linux does not review low power idle
bit to determine whether to offer S2I or S3

Is it something that is envisioned already as a future evolution in Linux as
well, if more and more systems are now designed with S2I in mind?

Eventually this will change, but for now first we need to sort out the problems
with the systems that do S2I.

quoted

so I'm inquiring if we can remove
S3 from a future BIOS update on this platform to let Linux work better
even though we don't ship this platform with Linux.

That would be a great fix, removing the default to S3 for this system on Linux.

quoted

For now I would recommend that you focus efforts exclusively on making
S2I work, and ignore S3 problems.

Well noted!

quoted

It's unclear to me exactly when you tested s2idle-dell-test.
Can you re-test with Rafael's newest submissions and changes to s2idle-dell-test
committed 28 hours ago?
You'll still have to add your system to the DMI whitelist for the last patch
but he has reworked a bunch of related wakeup code that has also changed.

I've just done so, using the updated s2idle-dell-test branch + my DMI
adaptation.

I still get exactly the same results than during my previous tests:
- it provides the expected fix when running BIOS 1.1.20: short press to wake-up
- it doesn't fix with the current BIOS 1.1.31: long press still needed
to wake-up
so something has clearly changed between these 2 versions. Btw, the EC is
explicitly updated when flashing version 1.1.31, that's one of the
visible steps.

Some assumptions now: either the SCI is ignored erroneously or it's
not interpreted correctly by the expected driver? I guess that's the 2
possibilities I'll try to investigate.

Well that's too bad.  Yes, you're correct that the EC has changed between
those versions.  Are you testing on or off AC adapter?  As far as I can tell 
the fix that went  into that was specifically related to power button 
handling off AC adapter.