linux-kernel - Re: Regression on Dell XPS13

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Date:   Wed, 18 Jan 2017 12:11:56 +0100
From:   Paul Menzel <pmenzel@...gen.mpg.de>
To:     "Rafael J. Wysocki" <rafael@...nel.org>,
        Mario Limonciello <mario.limonciello@...l.com>
Cc:     Thorsten Leemhuis <linux@...mhuis.info>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Tomas Winkler <tomas.winkler@...el.com>, jan@...dor.com,
        Alexander Usyskin <alexander.usyskin@...el.com>,
        linux-kernel@...r.kernel.org, Yu C Chen <yu.c.chen@...el.com>,
        Tomi Sarvela <tomi.p.sarvela@...el.com>,
        Daniel Blueman <daniel@...ra.org>,
        Len Brown <len.brown@...el.com>, linux-pm@...r.kernel.org
Subject: Re: Regression on Dell XPS13

Dear Rafael, dear Mario,


On 01/18/17 03:18, Rafael J. Wysocki wrote:
> Mario, thanks for CCing this to linux-pm.

Rafael, you should have also received the message, Mario answered to.

> On Tue, Jan 17, 2017 at 5:57 PM,  <Mario.Limonciello@...l.com> wrote:

>> Thanks for raising this topic and including me.
>> Suspend to Idle support in Linux as an alternative S3 on x86 is a new
>> topic.  In all, I expected that some problems would arise as a result
>> of this patch, and I hope they will spur interesting discussions and
>> solutions.
>>
>> Something that might not be immediately obvious is that by supporting
>> suspend to idle, new driver bugs are going to be identified for drivers
>> that don't properly put hardware into low enough power modes for the CPU
>> to go into the proper state.  Traditionally with S3 the BIOS would be responsible
>> for powering devices down before S3 and back up when exiting S3.
>> This onus is now on the OS.

That is fine, but then it shouldn’t be the default, until most of these 
bugs are identified and fixed.

Also, the commit message should make that more clear, and in my opinion 
the tested devices be listed.

>>> -----Original Message-----
>>> From: Paul Menzel [mailto:pmenzel@...gen.mpg.de]
>>> Sent: Tuesday, January 17, 2017 8:34 AM
>>> To: Rafael J. Wysocki <rafael.j.wysocki@...el.com>; Limonciello, Mario
>>> <Mario_Limonciello@...l.com>
>>> Cc: Thorsten Leemhuis <linux@...mhuis.info>; Greg Kroah-Hartman
>>> <gregkh@...uxfoundation.org>; Tomas Winkler <tomas.winkler@...el.com>;
>>> Jan Niehusmann <jan@...dor.com>; Usyskin, Alexander
>>> <alexander.usyskin@...el.com>; linux-kernel@...r.kernel.org; Chen, Yu C
>>> <yu.c.chen@...el.com>; Sarvela, Tomi P <tomi.p.sarvela@...el.com>; Daniel
>>> Blueman <daniel@...ra.org>; Len Brown <len.brown@...el.com>; linux-
>>> pm@...r.kernel.org
>>> Subject: Regression on Dell XPS13 (was: [char-misc for 4.10-rc4 V2] mei: bus:
>>> enable OS version only for SPT and newer)
>>>
>>> On 01/17/17 09:14, Thorsten Leemhuis wrote:
>>>> Greg Kroah-Hartman wrote on 16.01.2017 12:05:
>>>>> On Sun, Jan 15, 2017 at 11:58:30AM +0100, Greg Kroah-Hartman wrote:
>>>>>> On Sun, Jan 15, 2017 at 07:19:03AM +0000, Winkler, Tomas wrote:
>>>>>>>> Subject: Re: [char-misc for 4.10-rc4 V2] mei: bus: enable OS
>>>>>>>> version only for SPT and newer On Sat, Jan 14, 2017 at 08:27:31PM
>>>>>>>> +0100, Paul Menzel wrote:
>>>>>>>>> On 2017-01-13 14:00, Greg Kroah-Hartman wrote:
>>>>>>>>>> On Wed, Jan 11, 2017 at 03:26:06PM +0100, Paul Menzel wrote:
>>>>>>>>>>> On 01/11/17 15:12, Winkler, Tomas wrote:
>>>>>>>>>>>>>> On 01/11/17 10:24, Winkler, Tomas wrote:
>>>>>>>>>>>>>>>> On Wed, Jan 11, 2017 at 01:27:21AM +0200, Tomas Winkler wrote:
>>>>>>>>>>>>>>>>> On older platforms the command should be just ignored by
>>>>>>>>>>>>>>>>> the firmware but some older platforms misbehave so it's
>>>>>>>>>>>>>>>>> safer to send the command only if required.
>>>>>>>>>>>>>>>> Thanks! This fixes suspend-to-ram for me (on a Thinkpad x201s).
>>>>>>>>>>>>>>> What about Dell XPS13?
>>>
>>> There is a regression with Linux 4.10-rc{1,2,3} on the Intel Kaby Lake device
>>> Dell XPS13 (9360). Hitting the power button, the light of the power button
>>> never goes off. Pressing it again, nothing happen. Only pressing it like ten
>>> seconds the screen comes back for five seconds, and then it seems to try to
>>> suspend again.

> Can you please check if reverting commit 08b98d329165 (PM / sleep /
> ACPI: Use the ACPI_FADT_LOW_POWER_S0 flag) helps?

Didn’t the `git bisect` run already take care of that? Anyway, I built 
Linus’ master with the commit reverted, and `deep` is now indeed 
selected. No idea, if something else changed, or I messed up during 
bisection.

```
$ git log --oneline -2
b35b50125fec Revert "PM / sleep / ACPI: Use the ACPI_FADT_LOW_POWER_S0 flag"
0aa0313f9d57 Merge tag 'modules-for-v4.10-rc5' of 
git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux
$ more /sys/power/mem_sleep
s2idle [deep]
```

> If not, please send me the output of "cat /sys/power/mem_sleep" from
> the affected system.

I think it is `[s2idle] deep` when the bug occurred.

It *looks* like the BIOS indeed claims, that S0 saves more energy than S3.

```
$ sudo cat /sys/firmware/acpi/tables/FACP > facp.bin
$ iasl -d facp.bin
$ grep S0 facp.dsl
                       Low Power S0 Idle (V5) : 1
```


Kind regards,

Paul