[Intel-gfx] display problems since: drm/i915/dp: workaround BIOS eDP bpp clamping issue

[Daniel Vetter]

On Fri, Nov 1, 2013 at 9:02 PM, Cristian Rodríguez
<crrodriguez at opensuse.org> wrote:
> El 01/11/13 15:45, Daniel Vetter escribió:
>
>> On Fri, Nov 01, 2013 at 01:29:30PM -0300, Cristian Rodríguez wrote:
>>>
>>> Hi:
>>>
>>> I have a dell laptop XPS 15z, BIOS revision A12, in which a monitor
>>> is connected to the displayport .. everything was working OK until
>>> the very latest kernel merge.
>>>
>>> Now, when the monitor is plugged (but NOT when using the laptop
>>> display) the GPU freezes the screen for a few seconds, it is
>>> impossible to do anything other than waiting until it recovers.
>>>
>>> reverting commit c6cd2ee2d59111a07cd9199564c9bdcb2d11e5cf
>>> "drm/i915/dp: workaround BIOS eDP bpp clamping issue gets things
>>> back to the previous working status.
>>
>>
>> Can you please boot with drm.debug=0xe added to your kernel cmdline,
>> reproduce the issue and then attach the complete dmesg?
>>
>> Thanks, Daniel
>>
>
> Thanks for your quick reply, I appreciate that.
>
> Ok, I reverted my local tree to include the mentioned commit ...
> attached to this message is the requested log.
>
> the error shown after the freezing behaviour is:
>
> "[drm:ring_stuck] *ERROR* Kicking stuck wait on render ring"

Ok, gpu hang. Unfortunately this particular kernel doesn't bother to
dump the hang state in this case, so can you please test with the
latest drm-intel-nightly branch from

http://cgit.freedesktop.org/~danvet/drm-intel/

Dmesg should politely tell you to grab a file from sysfs once the gpu
ring is stuck again, please attach that.

Thanks, Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch