From: Lyude Paul <lyude@redhat.com>
Date: Mon, 14 Nov 2022 22:17:53 +0000 (-0500)
Subject: drm/display/dp_mst: Fix drm_dp_mst_add_affected_dsc_crtcs() return code
X-Git-Tag: v5.10.158~91
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=44b204730bf32131f064ebc90145092590c7fe95;p=thirdparty%2Fkernel%2Fstable.git

drm/display/dp_mst: Fix drm_dp_mst_add_affected_dsc_crtcs() return code

[ 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>
---

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 4272cd3622f8b..0feeac52e4eb3 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -5238,7 +5238,7 @@ 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) {