[PATCH 5.4 183/214] drm/amd/display: Avoid MST manager resource leak.

[Greg Kroah-Hartman]

From: Andrey Grodzovsky <andrey.grodzovsky@xxxxxxx>

commit 5dff80bdce9e385af5716ed083f9e33e814484ab upstream.

On connector destruction call drm_dp_mst_topology_mgr_destroy
to release resources allocated in drm_dp_mst_topology_mgr_init.
Do it only if MST manager was initilized before otherwsie a crash
is seen on driver unload/device unplug.

Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx>
Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@xxxxxxx>
Acked-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -3956,6 +3956,13 @@ static void amdgpu_dm_connector_destroy(
 	struct amdgpu_device *adev = connector->dev->dev_private;
 	struct amdgpu_display_manager *dm = &adev->dm;
 
+	/*
+	 * Call only if mst_mgr was iniitalized before since it's not done
+	 * for all connector types.
+	 */
+	if (aconnector->mst_mgr.dev)
+		drm_dp_mst_topology_mgr_destroy(&aconnector->mst_mgr);
+
 #if defined(CONFIG_BACKLIGHT_CLASS_DEVICE) ||\
 	defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE)