From: Eric Yang Eric.Yang2@amd.com
[ Upstream commit 0a14544661fad1606cc96aece30b2950fd9c4c81 ]
[Why] Megachip dockings accesses ddc line through display driver when installing FW. Previously, we would fail every transaction because link attached to mst branch did not have their ddc transaction type set.
[How] Set ddc transaction type when mst branch is connected.
Signed-off-by: Eric Yang Eric.Yang2@amd.com Reviewed-by: Charlene Liu Charlene.Liu@amd.com Acked-by: Harry Wentland harry.wentland@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- drivers/gpu/drm/amd/display/dc/core/dc_link.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c index 2fa521812d23..0351f7dc46e3 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c @@ -497,6 +497,10 @@ static bool detect_dp( sink_caps->signal = SIGNAL_TYPE_DISPLAY_PORT_MST; link->type = dc_connection_mst_branch;
+ dal_ddc_service_set_transaction_type( + link->ddc, + sink_caps->transaction_type); + /* * This call will initiate MST topology discovery. Which * will detect MST ports and add new DRM connector DRM