[PATCH 1/2] Revert "drm/radeon: remove drm_vblank_get|put from pflip handling"

[Michel Dänzer]

On 26.06.2014 08:34, Dieter Nützel wrote:
> Am 25.06.2014 09:57, schrieb Michel Dänzer:
>> On 25.06.2014 03:13, Dieter Nützel wrote:
>>> Am 24.06.2014 12:05, schrieb Michel Dänzer:
>>>> On 24.06.2014 05:32, Dieter Nützel wrote:
>>>>> Am 23.06.2014 21:46, schrieb Dieter Nützel:
>>>>>> Am 23.06.2014 11:34, schrieb Michel Dänzer:
>>>>>>> On 18.06.2014 18:14, Christian König wrote:
>>>>>>>> Am 18.06.2014 07:53, schrieb Michel Dänzer:
>>>>>>>>>
>>>>>>>>>   (WW) RADEON(0): radeon_dri2_flip_event_handler: Pageflip
>>>>>>>>> completion
>>>>>>>>> event has impossible msc [x-1] < target_msc [x]
>>>>> [...]
>>>>> I can reliable generate such lines in Xorg.0.log with KWin cube
>>>>> desktop
>>>>> effect.
>>>>>
>>>>> Rotate screens with mouse wheel or screen switcher => new entry in
>>>>> Xorg.0.log. If it happens I notice ('see') flip delay.
>>>>
>>>> [...]
>>>
>>> My daughter generated kernel crash for us.;-)
>>> See would open up a zoom image in Konqi of a new Waveboard for here girl
>>> friends...
>>>
>>> But I could only take images with my mobile.
>>> kernel BUG at drivers/gpu/drm/drm_irq.c:976!
>>
>> I was able to reproduce all these issues, and the attached three patches
>> fix them for me. Please let me know if you can still trigger the panic
>> or the diagnostic error messages in patch 2 somehow. If everything works
>> fine for you as well with these, I'll submit them with the error
>> messages in patch 2 changed to debug messages.
> 
> Tested-by: Dieter at nuetzel-hh.de on top of 3.16-rc2.
> Can't trigger any of the above problems with your three patches applied.

Great, thanks for testing. I've submitted the first two patches for
inclusion.

I'm still pondering if the third patch is the right thing to do or even
necessary. Maybe we should instead fix the X radeon driver to deal more
gracefully with page flips completing earlier than expected. E.g. weston
doesn't seem to have any trouble with that.


> Shouldn't this go into -rc3 if Christian and Alex ACKed it?

These fixes should go in before the 3.16 release, yes. And I don't see
why they wouldn't.


-- 
Earthling Michel Dänzer            |                  http://www.amd.com
Libre software enthusiast          |                Mesa and X developer