[Intel-gfx] [PATCH] drm/i915: Ignore panel type from OpRegion on SKL

[Ville Syrjälä]

On Wed, Jul 13, 2016 at 10:33:00PM +0900, James Bottomley wrote:
> On Tue, 2016-07-12 at 15:00 +0300, ville.syrjala at linux.intel.com wrote:
> > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > 
> > Dell XPS 13 9350 apparently doesn't like it when we use the panel
> > type
> > from OpRegion. The OpRegion panel type (0) tells us to use use low
> > vswing for eDP, whereas the VBT panel type (2) tells us to use normal
> > vswing. The problem is that low vswing results in some display
> > flickers.
> > Since no one seems to know how this stuff is supposed to be handled,
> > let's just ignore the OpRegion panel type on SKL for now.
> > 
> > Reported-by: James Bottomley <James.Bottomley at HansenPartnership.com>
> > Cc: James Bottomley <James.Bottomley at HansenPartnership.com>
> > Cc: drm-intel-fixes at lists.freedesktop.org
> > References: https://lists.freedesktop.org/archives/intel-gfx/2016-Jun
> > e/098826.html
> > Fixes: a05628195a0d ("drm/i915: Get panel_type from OpRegion panel
> > details")
> > Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> This one doesn't actually compile on git head:
> 
> 
> drivers/gpu/drm/i915/intel_opregion.c: In function
> ‘intel_opregion_get_panel_type’:
> drivers/gpu/drm/i915/intel_opregion.c:1047:17: error: ‘dev_priv’
> undeclared (first use in this function)
>   if (IS_SKYLAKE(dev_priv))
> 
> So it's going to be hard to backport to stable.

s/dev_priv/dev/ is probably all that's needed.

> 
> However, I've applied it on top of the drm branch and there have been
> no flicker problems after 12h of use, so you can add a tested by from
> me if you want.

Thanks.

-- 
Ville Syrjälä
Intel OTC