Re: Regression on Dell XPS13 (was: [char-misc for 4.10-rc4 V2] mei: bus: enable OS version only for SPT and newer)

[Rafael J. Wysocki]

On Sat, Jan 21, 2017 at 10:11 AM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Fri, Jan 20, 2017 at 11:11:45PM +0000, Mario.Limonciello@xxxxxxxx wrote:
>> Greg,
>>
>> > -----Original Message-----
>> > From: Darren Hart [mailto:dvhart@xxxxxxxxxxxxx]
>> > Sent: Tuesday, January 17, 2017 5:34 PM
>> > To: Limonciello, Mario <Mario_Limonciello@xxxxxxxx>
>> > Cc: gregkh@xxxxxxxxxxxxxxxxxxx; rafael.j.wysocki@xxxxxxxxx;
>> > pmenzel@xxxxxxxxxxxxx; linux@xxxxxxxxxxxxx; tomas.winkler@xxxxxxxxx;
>> > jan@xxxxxxxxxx; alexander.usyskin@xxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
>> > yu.c.chen@xxxxxxxxx; tomi.p.sarvela@xxxxxxxxx; daniel@xxxxxxxxx;
>> > len.brown@xxxxxxxxx; linux-pm@xxxxxxxxxxxxxxx
>> > Subject: Re: Regression on Dell XPS13 (was: [char-misc for 4.10-rc4 V2] mei:
>> > bus: enable OS version only for SPT and newer)
>> >
>> > On Tue, Jan 17, 2017 at 06:38:43PM +0000, Mario.Limonciello@xxxxxxxx
>> > wrote:
>> > > > -----Original Message-----
>> > > > From: Greg KH [mailto:gregkh@xxxxxxxxxxxxxxxxxxx]
>> > > > Sent: Tuesday, January 17, 2017 12:24 PM
>> > > > To: Limonciello, Mario <Mario_Limonciello@xxxxxxxx>
>> > > > Cc: pmenzel@xxxxxxxxxxxxx; rafael.j.wysocki@xxxxxxxxx;
>> > > > linux@xxxxxxxxxxxxx; tomas.winkler@xxxxxxxxx; jan@xxxxxxxxxx;
>> > > > alexander.usyskin@xxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
>> > > > yu.c.chen@xxxxxxxxx; tomi.p.sarvela@xxxxxxxxx; daniel@xxxxxxxxx;
>> > > > len.brown@xxxxxxxxx; linux-pm@xxxxxxxxxxxxxxx
>> > > > Subject: Re: Regression on Dell XPS13 (was: [char-misc for 4.10-rc4 V2] mei:
>> > > > bus: enable OS version only for SPT and newer)
>> > > >
>> > > > On Tue, Jan 17, 2017 at 04:57:49PM +0000, Mario.Limonciello@xxxxxxxx
>> > > > wrote:
>> > > > > So in the <6s scenario, the intel-hid driver is responsible to
>> > > > > receive the ACPI event and process accordingly.  The maintainer
>> > > > > has a patch ready for the intel-hid portion of this work, but it's
>> > > > > currently being reviewed by Intel to ensure it can be legally submitted
>> > into the kernel.
>> > > >
>> > > > Who at Intel do I need to go kick to make this mythical legal review
>> > > > happen faster so we can see the code?
>> > > >
>> > > > Len and Rafael, what is going on here?
>> > > >
>> > >
>> > > Len and Darren are both in the loop on the discussion around this patch.
>> > > I don't know if they'll have any (public) comments they can add on the
>> > > matter yet however.
>> >
>> > Thanks Mario. Yes, there isn't much to say here in public other than to confirm
>> > we are keenly aware of the problem and have been actively working on fixing
>> > it, both for this instance, and the deeper systematic failure that resulted in this
>> > situation. No amount of kicking will expedite the process at this point, but
>> > should we feel the need, we'll reach out.
>> >
>>
>> The approval has come through and the patch has been submitted.
>> http://www.spinics.net/lists/platform-driver-x86/msg10286.html
>
> Looks like it needs some work :)
>
> And why isn't it tagged to go to the 4.10-stable kernel if it really
> does fix some systems?
>
>> Note: this is only half of the fix, the second half needs the ACPI subsystem to
>> not be frozen to be able to receive this event.
>
> Where is that change?
>
> I'm still worried about 4.10-final, is that going to be broken for these
> types of systems?

Nope.

I'm going to revert commit 08b98d329165 (PM / sleep / ACPI: Use the
ACPI_FADT_LOW_POWER_S0 flag) which introduced the problem in the first
place (yes, the bisection result it misleading).  In fact, the revert
is in my linux-next branch already, but I'm sort of out in the woods
now and the actual pull request will be sent next week.

BTW, this is a usual process.  We had tried to change the default
behaviour for certain class of systems and it didn't work, so we need
to take a step back, fix the problems that were exposed and try again
later.

It has been confused quite a bit, though, which is kind of worrisome.

Thanks,
Rafael