[PATCH 5.15 010/120] drm/display/dp_mst: Fix drm_dp_mst_add_affected_dsc_crtcs() return code

Greg Kroah-Hartman
2022-12-05T19:36:39Z

From: Lyude Paul <lyude@redhat.com>

[ Upstream commit 2f3a1273862cb82cca227630cc7f04ce0c94b6bb ]

Looks like that we're accidentally dropping a pretty important return code
here. For some reason, we just return -EINVAL if we fail to get the MST
topology state. This is wrong: error codes are important and should never
be squashed without being handled, which here seems to have the potential
to cause a deadlock.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Wayne Lin <Wayne.Lin@amd.com>
Fixes: 8ec046716ca8 ("drm/dp_mst: Add helper to trigger modeset on affected DSC MST CRTCs")
Cc: <stable@vger.kernel.org> # v5.6+
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/drm_dp_mst_topology.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 9bf9430209b0..0d915fe8b6e4 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -5285,7 +5285,7 @@ int drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state, struct drm
mst_state = drm_atomic_get_mst_topology_state(state, mgr);

if (IS_ERR(mst_state))
- return -EINVAL;
+ return PTR_ERR(mst_state);

list_for_each_entry(pos, &mst_state->vcpis, next) {

--
2.35.1