[Intel-gfx] [KERNEL] Re: [KERNEL] Regression bug in drm/i915, Wrong assumption in commit e11aa36 breaks suspend on at least lenovo x61

[Daniel Vetter]

On Wed, Feb 18, 2015 at 8:03 PM, Klaus Ethgen <Klaus+lkml at ethgen.de> wrote:
> Am Mi den 18. Feb 2015 um 16:39 schrieb Jani Nikula:
>> On Tue, 17 Feb 2015, Klaus Ethgen <Klaus+lkml at ethgen.de> wrote:
>> > After solving  the conflicts, I applied the revert (see attachment) to
>> > v3.18.7. I think it should also apply to the current head. With that
>> > patch, suspend is working again on that version.
>> >
>> > However, I have not to deep knowledge of that subsystem, so please,
>> > someone who have, have a deeper look into it. I especially do not know
>> > if the lines in .../intel_pm.c are correct or better leaving them as
>> > they are in v3.18.7.
>> >
>> > I want to have it working on a version that I know is stable before
>> > asking to pull it to head.
>>
>> Hi Klaus, we fear this patch may hide the actual cause.
>
> That might be. But that might be a second step, to find the actual
> cause. I think first the patch that causes the problem should be
> fixed/reverted to have a working kernel and the next step would be to
> find the real cause.

I think the rever also breaks soix on newer platforms. Instead I think
intel_runtime_pm_disable_interrupts needs to grow a synchronize_irq()
after having disabled all the interrupt sources. But that's just
drive-by debugging, I might be off the charts ;-)
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch