Hi Kieran, Thank you for the patch. On Wednesday, 19 September 2018 18:56:58 EEST Kieran Bingham wrote: > Planes without an alpha property, using __drm_atomic_helper_plane_reset > will have their plane state alpha initialised as zero, which represents > a transparent alpha. > > If this value is then used for the plane, it may not be visible by > default, and thus doesn't represent a good initialisation state. > > Update the default state->alpha value to DRM_BLEND_ALPHA_OPAQUE > unconditionally when the plane is reset. > > Signed-off-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx> I believe the decision to use plane->alpha_property->values[1] instead of hardcoding DRM_BLEND_ALPHA_OPAQUE comes from earlier versions of the alpha patch series that supported driver-specific ranges for the alpha value. The current implementation uses DRM_BLEND_ALPHA_OPAQUE unconditionally, and no driver modifies the maximum value behind the scene, so Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> > --- > drivers/gpu/drm/drm_atomic_helper.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c > b/drivers/gpu/drm/drm_atomic_helper.c index 3cf1aa132778..e49b22381048 > 100644 > --- a/drivers/gpu/drm/drm_atomic_helper.c > +++ b/drivers/gpu/drm/drm_atomic_helper.c > @@ -3569,9 +3569,7 @@ void __drm_atomic_helper_plane_reset(struct drm_plane > *plane, state->plane = plane; > state->rotation = DRM_MODE_ROTATE_0; > > - /* Reset the alpha value to fully opaque if it matters */ > - if (plane->alpha_property) > - state->alpha = plane->alpha_property->values[1]; > + state->alpha = DRM_BLEND_ALPHA_OPAQUE; > state->pixel_blend_mode = DRM_MODE_BLEND_PREMULTI; > > plane->state = state; -- Regards, Laurent Pinchart
