[PATCH v3 3/6] drm: rcar-du: Only initialise TVM_TVSYNC mode when supported

[Kieran Bingham]

The R-Car DU as found on the D3, E3, and V3U do not have support
for an external synchronisation method.

In these cases, the dsysr cached register should not be initialised
in DSYSR_TVM_TVSYNC, but instead should be left clear to configure as
DSYSR_TVM_MASTER by default.

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>

---
v2:
 - Remove parenthesis

 drivers/gpu/drm/rcar-du/rcar_du_crtc.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
index ea7e39d03545..a0f837e8243a 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
@@ -1243,7 +1243,10 @@ int rcar_du_crtc_create(struct rcar_du_group *rgrp, unsigned int swindex,
 	rcrtc->group = rgrp;
 	rcrtc->mmio_offset = mmio_offsets[hwindex];
 	rcrtc->index = hwindex;
-	rcrtc->dsysr = (rcrtc->index % 2 ? 0 : DSYSR_DRES) | DSYSR_TVM_TVSYNC;
+	rcrtc->dsysr = rcrtc->index % 2 ? 0 : DSYSR_DRES;
+
+	if (rcar_du_has(rcdu, RCAR_DU_FEATURE_TVM_SYNC))
+		rcrtc->dsysr |= DSYSR_TVM_TVSYNC;
 
 	if (rcar_du_has(rcdu, RCAR_DU_FEATURE_VSP1_SOURCE))
 		primary = &rcrtc->vsp->planes[rcrtc->vsp_pipe].plane;
-- 
2.30.2