drm/amd/display: Fix allocate_mst_payload assert on resume

stable inclusion
from stable-v5.10.112
commit 4b44cd5840577479ee6ed387371dd1d1252ca921
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5HL0X

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4b44cd5840577479ee6ed387371dd1d1252ca921

--------------------------------

[ Upstream commit f4346fb3 ]

[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: NWayne Lin <Wayne.Lin@amd.com>
Acked-by: NAlex Hung <alex.hung@amd.com>
Signed-off-by: NRoman Li <Roman.Li@amd.com>
Tested-by: NDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -2022,7 +2022,8 @@ 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);