drm/amd/display: Add audio support for DFP type of active branch is DP case

[Why]
Per DP spec, for active protocol convertor adaptor, DP source should enable audio
for DFP type is DP, HDMI or DP++. Current is_dp_active_dongle() checking is not
precise, which treat branch device default as active dongle. As a result, we will
mistakenly disable audio for DFP type is DP case.

[How]
Make is_dp_active_dongle() checking more precise for active dongle types.
Rename active diongle type as SST branch device in case confusion.

Signed-off-by: Dale Zhao <dale.zhao@amd.com>
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Wayne Lin <Wayne.Lin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h b/drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h
index 3ae05c96d557..699de64a7e44 100644
--- a/drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h
+++ b/drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h
@@ -75,6 +75,8 @@ void detect_edp_sink_caps(struct dc_link *link);
 
 bool is_dp_active_dongle(const struct dc_link *link);
 
+bool is_dp_branch_device(const struct dc_link *link);
+
 bool is_edp_ilr_optimization_required(struct dc_link *link, struct dc_crtc_timing *crtc_timing);
 
 void dp_enable_mst_on_sink(struct dc_link *link, bool enable);