[Regression][v3.17][3.18][3.19-rc3] drm/radeon: re-enable dpm by default on BTC

[Joseph Salisbury]

On 01/07/2015 09:51 PM, Deucher, Alexander wrote:
>
>> -----Original Message-----
>> From: Joseph Salisbury [mailto:joseph.salisbury at canonical.com]
>> Sent: Wednesday, January 07, 2015 5:51 PM
>> To: Deucher, Alexander
>> Cc: stable at vger.kernel.org; LKML; Koenig, Christian; David Airlie; dri-devel
>> Subject: [Regression][v3.17][3.18][3.19-rc3] drm/radeon: re-enable dpm by
>> default on BTC
>>
>> Hi Alexander,
>>
>> A kernel bug report was opened against Ubuntu [0].  After a kernel
>> bisect, it was found that reverting the following commit resolved this bug:
>>
>> commit c08abf11900e19b14dd3a0cc3d105bd74519cd18
>> Author: Alex Deucher <alexander.deucher at amd.com>
>> Date:   Mon Jul 14 12:01:40 2014 -0400
>>
>>     drm/radeon: re-enable dpm by default on BTC
>>
>> The regression was introduced as of v3.17-rc1 and still exists in
>> current mainline.  It has also made it's way into the stable releases.
>>
>> I was hoping to get your feedback, since you are the patch author.  Do
>> you think gathering any additional data will help diagnose this issue,
>> or would it be best to submit a revert request?
>>
> Does revering b2dccf24e77 help?  I'd hate to revert this patch because it disables power management for a whole family of chips.  If it doesn't help I'd prefer to just add a quirk to disable it for the specific problematic board.
We'll test and let you know.  Thanks for the feedback, Alex!


>
> Alex
>
>> Thanks,
>>
>> Joe
>>
>> [0] http://pad.lv/1386534