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

From: Deucher, Alexander
Date: Wed Jan 07 2015 - 22:06:29 EST




> -----Original Message-----
> From: Joseph Salisbury [mailto:joseph.salisbury@xxxxxxxxxxxxx]
> Sent: Wednesday, January 07, 2015 5:51 PM
> To: Deucher, Alexander
> Cc: stable@xxxxxxxxxxxxxxx; 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@xxxxxxx>
> 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.

Alex

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