From: Michael Strauss <michael.strauss@xxxxxxx>
[WHY]
Many DCN generations only have two HPO link encoders and therefore only
support driving a max of two DP2 PHYs. DP2 MST hubs currently can not
pass 3x display validation as each downstream sink is enumerated as
separate DP2 output.
[HOW]
Count MST hubs once by treating only 1st remote sink in topology as an
encoder.
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx>
Acked-by: Rodrigo Siqueira <rodrigo.siqueira@xxxxxxx>
Signed-off-by: Michael Strauss <michael.strauss@xxxxxxx>
---
drivers/gpu/drm/amd/display/dc/dml2/dml2_utils.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/dc/dml2/dml2_utils.c b/drivers/gpu/drm/amd/display/dc/dml2/dml2_utils.c
index 33eab80e89a8..6ba393e5b8ee 100644
--- a/drivers/gpu/drm/amd/display/dc/dml2/dml2_utils.c
+++ b/drivers/gpu/drm/amd/display/dc/dml2/dml2_utils.c
@@ -157,6 +157,15 @@ bool is_dp2p0_output_encoder(const struct pipe_ctx *pipe_ctx)
{
/* If this assert is hit then we have a link encoder dynamic management issue */
ASSERT(pipe_ctx->stream_res.hpo_dp_stream_enc ? pipe_ctx->link_res.hpo_dp_link_enc != NULL : true);
+
+ /* Count MST hubs once by treating only 1st remote sink in topology as an encoder */
+ if (pipe_ctx->stream->link && pipe_ctx->stream->link->remote_sinks[0]) {
+ return (pipe_ctx->stream_res.hpo_dp_stream_enc &&
+ pipe_ctx->link_res.hpo_dp_link_enc &&
+ dc_is_dp_signal(pipe_ctx->stream->signal) &&
+ (pipe_ctx->stream->link->remote_sinks[0] == pipe_ctx->stream->sink));
+ }
+
return (pipe_ctx->stream_res.hpo_dp_stream_enc &&
pipe_ctx->link_res.hpo_dp_link_enc &&
dc_is_dp_signal(pipe_ctx->stream->signal));
--
2.42.0
