On Tue, Jul 12, 2016 at 03:00:37PM +0300, ville.syrjala@xxxxxxxxxxxxxxx wrote: > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > 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@xxxxxxxxxxxxxxxxxxxxx> > Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> > Cc: drm-intel-fixes@xxxxxxxxxxxxxxxxxxxxx > References: https://lists.freedesktop.org/archives/intel-gfx/2016-June/098826.html > Fixes: a05628195a0d ("drm/i915: Get panel_type from OpRegion panel details") > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Oh well, but not really a better option unfortunately. Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx> Could also be that this is more general on newer machines ... Did you check latest OpRegion spec to make sure this isn't deprecated? -Daniel > --- > drivers/gpu/drm/i915/intel_opregion.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c > index c27d5eb063d0..259760f12d16 100644 > --- a/drivers/gpu/drm/i915/intel_opregion.c > +++ b/drivers/gpu/drm/i915/intel_opregion.c > @@ -1072,5 +1072,16 @@ intel_opregion_get_panel_type(struct drm_i915_private *dev_priv) > return -ENODEV; > } > > + /* > + * FIXME On Dell XPS 13 9350 the OpRegion panel type (0) gives us > + * low vswing for eDP, whereas the VBT panel type (2) gives us normal > + * vswing instead. Low vswing results in some display flickers, so > + * let's simply ignore the OpRegion panel type on SKL for now. > + */ > + if (IS_SKYLAKE(dev_priv)) { > + DRM_DEBUG_KMS("Ignoring OpRegion panel type (%d)\n", ret); > + return -ENODEV; > + } > + > return ret - 1; > } > -- > 2.7.4 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
