diff options
| author | Wayne Lin <Wayne.Lin@amd.com> | 2025-11-05 10:36:31 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-11-13 15:34:39 -0500 |
| commit | aa4be25f41f343b23d3ef6cb344740e03a72d7cf (patch) | |
| tree | f2a3a663e2df7cf501c091bf7b6d3825cc935f96 | |
| parent | dc387c6def4dd39ac072673c797b58869151104f (diff) | |
| download | linux-aa4be25f41f343b23d3ef6cb344740e03a72d7cf.tar.gz linux-aa4be25f41f343b23d3ef6cb344740e03a72d7cf.tar.bz2 linux-aa4be25f41f343b23d3ef6cb344740e03a72d7cf.zip | |
drm/amd/display: Enable mst when it's detected but yet to be initialized
commit 3c6a743c6961cc2cab453b343bb157d6bbbf8120 upstream.
[Why]
drm_dp_mst_topology_queue_probe() is used under the assumption that
mst is already initialized. If we connect system with SST first
then switch to the mst branch during suspend, we will fail probing
topology by calling the wrong API since the mst manager is yet to
be initialized.
[How]
At dm_resume(), once it's detected as mst branc connected, check if
the mst is initialized already. If not, call
dm_helpers_dp_mst_start_top_mgr() instead to initialize mst
V2: Adjust the commit msg a bit
Fixes: bc068194f548 ("drm/amd/display: Don't write DP_MSTM_CTRL after LT")
Cc: Fangzhi Zuo <jerry.zuo@amd.com>
Cc: Mario Limonciello <mario.limonciello@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 62320fb8d91a0bddc44a228203cfa9bfbb5395bd)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 10 |
1 files changed, 9 insertions, 1 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 271710104f0e..cd8c6887a3b5 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -3424,6 +3424,7 @@ static int dm_resume(void *handle) /* Do mst topology probing after resuming cached state*/ drm_connector_list_iter_begin(ddev, &iter); drm_for_each_connector_iter(connector, &iter) { + bool init = false; if (connector->connector_type == DRM_MODE_CONNECTOR_WRITEBACK) continue; @@ -3433,7 +3434,14 @@ static int dm_resume(void *handle) aconnector->mst_root) continue; - drm_dp_mst_topology_queue_probe(&aconnector->mst_mgr); + scoped_guard(mutex, &aconnector->mst_mgr.lock) { + init = !aconnector->mst_mgr.mst_primary; + } + if (init) + dm_helpers_dp_mst_start_top_mgr(aconnector->dc_link->ctx, + aconnector->dc_link, false); + else + drm_dp_mst_topology_queue_probe(&aconnector->mst_mgr); } drm_connector_list_iter_end(&iter); |