FAILED: patch "[PATCH] drm/display/dp_mst: Fix drm_dp_mst_add_affected_dsc_crtcs()" failed to apply to 5.15-stable tree

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

Possible dependencies:

a3ae99598b9f ("drm/display/dp_mst: Fix drm_dp_mst_add_affected_dsc_crtcs() return code")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From a3ae99598b9f89dd5ac9d2900fb7ffb3dcfa3d35 Mon Sep 17 00:00:00 2001
From: Lyude Paul <[email protected]>
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

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.

index ecd22c038c8c..51a46689cda7 100644
@@ -5186,7 +5186,7 @@ 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->payloads, next) {