On 2/9/2025 1:42 PM, Marijn Suijten wrote:
When DSC is enabled the number of interfaces is forced to be 1, and
documented that it is a "power-optimal" layout to use two DSC encoders
together with two Layer Mixers. However, the same layout (two DSC
hard-slice encoders with two LMs) is also used when the display is
fed with data over two instead of one interface (common on 4k@120Hz
smartphone panels with Dual-DSI). Solve this by simply removing the
num_intf = 1 assignment as the count is already calculated by computing
the number of physical encoders within the virtual encoder.
Fixes: 7e9cc175b159 ("drm/msm/disp/dpu1: Add support for DSC in topology")
Signed-off-by: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx>
Reviewed-by: Jessica Zhang <quic_jesszhan@xxxxxxxxxxx>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index b585cd17462345f94bcc2ddd57902cc7c312ae63..b0870318471bd7cceda70fd15ea7bcc8658af604 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -686,20 +686,21 @@ static struct msm_display_topology dpu_encoder_get_topology(
if (dsc) {
/*
- * Use 2 DSC encoders and 2 layer mixers per single interface
+ * Use 2 DSC encoders, 2 layer mixers and 1 or 2 interfaces
* when Display Stream Compression (DSC) is enabled,
* and when enough DSC blocks are available.
* This is power-optimal and can drive up to (including) 4k
* screens.
*/
- if (dpu_kms->catalog->dsc_count >= 2) {
+ WARN(topology.num_intf > 2,
+ "DSC topology cannot support more than 2 interfaces\n");
+ if (intf_count >= 2 || dpu_kms->catalog->dsc_count >= 2) {
topology.num_dsc = 2;
topology.num_lm = 2;
} else {
topology.num_dsc = 1;
topology.num_lm = 1;
}
- topology.num_intf = 1;
}
return topology;
--
2.48.1
