On Tue, Nov 20, 2018 at 02:25:40PM -0800, Rodrigo Vivi wrote:
> On Tue, Nov 20, 2018 at 03:54:49PM +0200, Ville Syrjala wrote:
> > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> >
> > If we force a plane update to fix up our half populated plane state
> > we'll also force on the pipe gamma for the plane (since we always
> > enable pipe gamma currently). If the BIOS hasn't programmed a sensible
> > LUT into the hardware this will cause the image to become corrupted.
> > Typical symptoms are a purple/yellow/etc. flash when the driver loads.
> >
> > To avoid this let's program something sensible into the LUT when
> > we do the plane update. In the future I plan to add proper plane
> > gamma enable readout so this is just a temporary measure.
>
> Since this is temporary and marked with FIXME and Hans confirmed
> it solves the best behaviour let's move with this.
>
> But I'm wondering if there is no way to minimize this instead of
> forcing this to every commit for each crtc...
It's just for the first commit we do when loading the driver.
>
> Anyway,
>
> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
>
> >
> > Cc: Hans de Goede <hdegoede@xxxxxxxxxx>
> > Fixes: 516a49cc1946 ("drm/i915: Fix assert_plane() warning on bootup with external display")
> > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/intel_display.c | 8 ++++++++
> > 1 file changed, 8 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > index 132e978227fb..60c1e54285c1 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -15011,6 +15011,14 @@ static int intel_initial_commit(struct drm_device *dev)
> > ret = drm_atomic_add_affected_planes(state, crtc);
> > if (ret)
> > goto out;
> > +
> > + /*
> > + * FIXME hack to force a LUT update to avoid the
> > + * plane update forcing the pipe gamma on without
> > + * having a proper LUT loaded. Remove once we
> > + * have readout for pipe gamma enable.
> > + */
> > + crtc_state->color_mgmt_changed = true;
> > }
> > }
> >
> > --
> > 2.18.1
> >
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Ville Syrjälä
Intel
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
