From f4346fb3edf7720db3f7f5e1cab1f667cd024280 Mon Sep 17 00:00:00 2001
From: Roman Li <Roman.Li@amd.com>
Date: Thu, 17 Mar 2022 19:55:05 -0400
Subject: [PATCH] drm/amd/display: Fix allocate_mst_payload assert on resume
Git-commit: f4346fb3edf7720db3f7f5e1cab1f667cd024280
Patch-mainline: v5.18-rc2
References: git-fixes

[Why]
On resume we do link detection for all non-MST connectors.
MST is handled separately. However the condition for telling
if connector is on mst branch is not enough for mst hub case.
Link detection for mst branch link leads to mst topology reset.
That causes assert in dc_link_allocate_mst_payload()

[How]
Use link type as indicator for mst link.

Reviewed-by: Wayne Lin <Wayne.Lin@amd.com>
Acked-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Roman Li <Roman.Li@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index b30656959fd8..5895afefccb7 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -2714,7 +2714,8 @@ static int dm_resume(void *handle)
 		 * this is the case when traversing through already created
 		 * MST connectors, should be skipped
 		 */
-		if (aconnector->mst_port)
+		if (aconnector->dc_link &&
+		    aconnector->dc_link->type == dc_connection_mst_branch)
 			continue;
 
 		mutex_lock(&aconnector->hpd_lock);
-- 
2.31.1