diff options
| author | LUU HOAI <hoai.luu.ub@renesas.com> | 2022-04-26 09:41:57 +0100 |
|---|---|---|
| committer | Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> | 2022-07-07 05:24:36 +0300 |
| commit | b7aaa61726cbc7b941007af14a9f991a828c67e4 (patch) | |
| tree | ab2ea8622e0d2d2eb8672d60a76c7ca616385b97 /drivers/gpu/drm/rcar-du | |
| parent | 3e7f74dcfb7233ba3f8b3879066fdd3e79f2f701 (diff) | |
drm: rcar-du: Fix Alpha blending issue on Gen3
As per R-Car-Gen3_Common_OPC_Customer_Notifications_V30.1.pdf,
unexpected image output(such as incorrect colors or planes being
invisible) can happen on the below conditions, as PnALPHAR register
is not initialized by reset.
When alpha blending (PpMRm.PpSPIM=0b101) is performed and:
•two Planes are enabled on any DUn (n=0,1,2,3)
oDSPRn= 0x0000 0031 or 0x0000 0013
•or DU0 and DU1 is used for display at the same time
oDSPR0= 0x0000 0001 and DSPR1= 0x0000 0003
oDSPR0= 0x0000 0003 and DSPR1= 0x0000 0001
•or DU2 and DU3(H3 Only) is used for display at the same time
oDSPR2= 0x0000 0001 and DSPR3= 0x0000 0003
oDSPR2= 0x0000 0003 and DSPR3= 0x0000 0001
This patch set PnALPHAR register to 0 to avoid this issue.
Signed-off-by: LUU HOAI <hoai.luu.ub@renesas.com>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Diffstat (limited to 'drivers/gpu/drm/rcar-du')
| -rw-r--r-- | drivers/gpu/drm/rcar-du/rcar_du_plane.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_plane.c b/drivers/gpu/drm/rcar-du/rcar_du_plane.c index 9a9bc8bcda30..501d79367e3e 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_plane.c +++ b/drivers/gpu/drm/rcar-du/rcar_du_plane.c @@ -512,6 +512,18 @@ 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, |