On Wed, Sep 29, 2021 at 09:54:14AM +0000, Simon Ser wrote: > When a plane is missing the "alpha blend mode" property, KMS drivers > will use the pre-multiplied mode. > > Signed-off-by: Simon Ser <contact@xxxxxxxxxxx> > Cc: Daniel Vetter <daniel@xxxxxxxx> > Cc: Pekka Paalanen <ppaalanen@xxxxxxxxx> Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Another option would be to sprinkle immutable props to all drivers that claim to do alpha blending and don't currently expose the property. > --- > drivers/gpu/drm/drm_blend.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/gpu/drm/drm_blend.c b/drivers/gpu/drm/drm_blend.c > index ec37cbfabb50..eebb32ba84d7 100644 > --- a/drivers/gpu/drm/drm_blend.c > +++ b/drivers/gpu/drm/drm_blend.c > @@ -185,6 +185,9 @@ > * plane does not expose the "alpha" property, then this is > * assumed to be 1.0 > * > + * When a plane is missing this property, the plane uses the > + * "Pre-multiplied" equation. > + * > * Note that all the property extensions described here apply either to the > * plane or the CRTC (e.g. for the background color, which currently is not > * exposed and assumed to be black). > -- > 2.33.0 > -- Ville Syrjälä Intel
