Re: [char-misc for 4.10-rc4 V2] mei: bus: enable OS version only for SPT and newer

Paul Menzel
2017-01-11T14:26:11Z

Dear Tomas,

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?
>>>
>>> With Linus' master branch from today, and Greg's char-misc-linus
>>> merged
>>> (Merge: 807b93e995d1 546cf3ef9c92), the regression is still there.
>>
>> Hmm, this should work on KBL....
>>
>>> I am now building a Linux kernel image with the two commits touching
>>> `bus- fixup.c` reverted.
>>
>> Thanks for the effort.
>>
>>> Do you want me to open a separate bug report for that, or continue
>>> debugging in the existing report [1], which is currently marked as resolved?
>>
>> Let's get some more data, shouldn't take long time.
>>>
>>> Do you have Kaby Lake devices sitting around for testing?
>>
>> We will of course try to reproduce the issue locally.
>
> Paul, currently we cannot reproduce this issue on Kaby Lake platforms on our side,

It looks like it’s a different issue. Reverting the two commits touching
`bus-fixup.c`, did not help.

> we would be great for more debug data from your side.
> You can get more info by enabling mode debug logs
>
> echo -n 'module mei +lfp' > /sys/kernel/debug/dynamic_debug/control
> echo -n 'module mei_me +lfp' > /sys/kernel/debug/dynamic_debug/control

I am currently bisecting to find the culprit. 13 steps will take some
time though.

Tomas, I believe Intel’s “ACPI department” got access to a Dell XPS13.

Kind regards,

Paul