[Intel-gfx] Bad flicker on skylake HQD due to code in the 4.7 merge window

[Jani Nikula]

Cc: Ville

On Mon, 20 Jun 2016, James Bottomley <James.Bottomley at HansenPartnership.com> wrote:
> OK, my candidate bad commit is this one:
>
> commit a05628195a0d9f3173dd9aa76f482aef692e46ee
> Author: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Date:   Mon Apr 11 10:23:51 2016 +0300
>
>     drm/i915: Get panel_type from OpRegion panel details
>
> After being more careful about waiting to identify flicker, this one
> seems to be the one the bisect finds.  I'm now running v4.7-rc3 with
> this one reverted and am currently seeing no flicker problems.  It is,
> however, early days because the flicker can hide for long periods, so I
> 'll wait until Monday evening and a few reboots before declaring
> victory.

If that turns out to be the bad commit, it doesn't really surprise me,
and that in itself is depressing.

It might be helpful if you could add drm.debug=14 module parameter, and
provide dmesgs from boot both with and without the above commit (it's
enough to see i915 load). Please also provide
/sys/kernel/debug/dri/0/i915_opregion.

BR,
Jani.

-- 
Jani Nikula, Intel Open Source Technology Center