diff options
Diffstat (limited to 'drivers/gpu/drm/rcar-du/rcar_du_plane.c')
| -rw-r--r-- | drivers/gpu/drm/rcar-du/rcar_du_plane.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_plane.c b/drivers/gpu/drm/rcar-du/rcar_du_plane.c index 8e729cc4c209..07ba6bff5f5d 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_plane.c +++ b/drivers/gpu/drm/rcar-du/rcar_du_plane.c @@ -1,6 +1,6 @@ // SPDX-License-Identifier: GPL-2.0+ /* - * rcar_du_plane.c -- R-Car Display Unit Planes + * R-Car Display Unit Planes * * Copyright (C) 2013-2015 Renesas Electronics Corporation * @@ -511,6 +511,18 @@ static void rcar_du_plane_setup_format_gen3(struct rcar_du_group *rgrp, rcar_du_plane_write(rgrp, index, PnDDCR4, state->format->edf | PnDDCR4_CODE); + + /* + * On Gen3, some DU channels have two planes, each being wired to a + * separate VSPD instance. The DU can then blend two planes. While + * this feature isn't used by the driver, issues related to alpha + * blending (such as incorrect colors or planes being invisible) may + * still occur if the PnALPHAR register has a stale value. Set the + * register to 0 to avoid this. + */ + + /* TODO: Check if alpha-blending should be disabled in PnMR. */ + rcar_du_plane_write(rgrp, index, PnALPHAR, 0); } static void rcar_du_plane_setup_format(struct rcar_du_group *rgrp, |