From 0a14544661fad1606cc96aece30b2950fd9c4c81 Mon Sep 17 00:00:00 2001 From: Eric Yang Date: Tue, 12 Jun 2018 18:37:12 -0400 Subject: [PATCH] drm/amd/display: support access ddc for mst branch [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 Reviewed-by: Charlene Liu Acked-by: Harry Wentland Signed-off-by: Alex Deucher --- 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 fa56c0f..a4180ba 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c @@ -498,6 +498,10 @@ 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 -- 2.7.4