This is a note to let you know that I've just added the patch titled drm/radeon: Fix a missing check bug in radeon_dp_mst_detect() to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-radeon-fix-a-missing-check-bug-in-radeon_dp_mst_.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 7f4428d6166c7a1847137a91f1570feb58d61046 Author: Yingjie Wang <wangyingjie55@xxxxxxx> Date: Tue Apr 6 20:10:04 2021 -0700 drm/radeon: Fix a missing check bug in radeon_dp_mst_detect() [ Upstream commit 25315ebfaefcffd126a266116b37bb8a3d1c4620 ] In radeon_dp_mst_detect(), We should check whether or not @connector has been unregistered from userspace. If the connector is unregistered, we should return disconnected status. Fixes: 9843ead08f18 ("drm/radeon: add DisplayPort MST support (v2)") Signed-off-by: Yingjie Wang <wangyingjie55@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/gpu/drm/radeon/radeon_dp_mst.c b/drivers/gpu/drm/radeon/radeon_dp_mst.c index 008308780443..9bd6c0697538 100644 --- a/drivers/gpu/drm/radeon/radeon_dp_mst.c +++ b/drivers/gpu/drm/radeon/radeon_dp_mst.c @@ -242,6 +242,9 @@ radeon_dp_mst_detect(struct drm_connector *connector, to_radeon_connector(connector); struct radeon_connector *master = radeon_connector->mst_port; + if (drm_connector_is_unregistered(connector)) + return connector_status_disconnected; + return drm_dp_mst_detect_port(connector, ctx, &master->mst_mgr, radeon_connector->port); }