From 2f3a1273862cb82cca227630cc7f04ce0c94b6bb Mon Sep 17 00:00:00 2001
From: Lyude Paul <lyude@redhat.com>
Date: Mon, 14 Nov 2022 17:17:53 -0500
Subject: [PATCH] drm/display/dp_mst: Fix drm_dp_mst_add_affected_dsc_crtcs() return code
Git-commit: 2f3a1273862cb82cca227630cc7f04ce0c94b6bb
Patch-mainline: v6.1-rc7
References: git-fixes
Alt-commit: a3ae99598b9f89dd5ac9d2900fb7ffb3dcfa3d35

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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/display/drm_dp_mst_topology.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/display/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c
@@ -5293,7 +5293,7 @@ int drm_dp_mst_add_affected_dsc_crtcs(st
 	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->payloads, next) {