From: Fangzhi Zuo jerry.zuo@amd.com

At drm suspend sequence, MST dc_sink is removed. When commit cached MST stream back in drm resume sequence, the MST stream payload is not properly created and added into the payload table. After resume, topology change is reprobed by removing existing streams first. That leads to no payload is found in the existing payload table as below error "[drm] ERROR No payload for [MST PORT:] found in mst state"

1. In encoder .atomic_check routine, remove check existance of dc_sink 2. Bypass MST by checking existence of MST root port. dc_link_type cannot differentiate MST port before topology is rediscovered.

Reviewed-by: Wayne Lin wayne.lin@amd.com Acked-by: Tom Chung chiahsuan.chung@amd.com Signed-off-by: Fangzhi Zuo jerry.zuo@amd.com Tested-by: Daniel Wheeler daniel.wheeler@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org (cherry picked from commit 52b112049e1da404828102ccb5b39e92d40f06d4) Adjusted for variables that were renamed between 6.1 and 6.3. Signed-off-by: Mario Limonciello mario.limonciello@amd.com --- This commit was tagged for stable but didn't apply due to variable name changes. It's important for MST during suspend/resume so I did the necessary manual fixups.

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

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 b46732cefe37..8ab0dd799b3c 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -2763,7 +2763,7 @@ static int dm_resume(void *handle) * this is the case when traversing through already created * MST connectors, should be skipped */ - if (aconnector->dc_link->type == dc_connection_mst_branch) + if (aconnector && aconnector->mst_port) continue;

mutex_lock(&aconnector->hpd_lock); @@ -6492,7 +6492,7 @@ static int dm_encoder_helper_atomic_check(struct drm_encoder *encoder, int clock, bpp = 0; bool is_y420 = false;

- if (!aconnector->port || !aconnector->dc_sink) + if (!aconnector->port) return 0;

mst_port = aconnector->port;