[PATCH] drm/msm/dpu: Only enable DSC_MODE_MULTIPLEX if dsc_merge is enabled

[Marijn Suijten <marijn.suijten@somainline.org>]

When the topology calls for two interfaces on the current fixed topology
of 2 DSC blocks, or uses 1 DSC block for a single interface (e.g. SC7280
with only one DSC block), there should be no merging of DSC output.

This is already represented by the return value of
dpu_encoder_use_dsc_merge(), but not yet used to correctly configure
this flag.

Fixes: 58dca9810749 ("drm/msm/disp/dpu1: Add support for DSC in encoder")
Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
---
Note that more changes are needed to properly support the proposed 2:2:2
and 1:1:1 topology (in contrast to the already-supported 2:2:1 topology),
but this could be a trivial patch to get going separately before all that
extra work is done.
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index 83380bc92a00..6d3ed4d870d7 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -1857,7 +1857,9 @@ static void dpu_encoder_prep_dsc(struct dpu_encoder_virt *dpu_enc,
 	dsc_common_mode = 0;
 	pic_width = dsc->pic_width;
 
-	dsc_common_mode = DSC_MODE_MULTIPLEX | DSC_MODE_SPLIT_PANEL;
+	dsc_common_mode = DSC_MODE_SPLIT_PANEL;
+	if (dpu_encoder_use_dsc_merge(enc_master->parent))
+		dsc_common_mode |= DSC_MODE_MULTIPLEX;
 	if (enc_master->intf_mode == INTF_MODE_VIDEO)
 		dsc_common_mode |= DSC_MODE_VIDEO;
 

---
base-commit: 01af33cc9894b4489fb68fa35c40e9fe85df63dc
change-id: 20240204-dpu-dsc-multiplex-49c14b73f3e0

Best regards,
-- 
Marijn Suijten <marijn.suijten@somainline.org>