FAILED: patch "[PATCH] drm/amd/display: check if dml21_add_phantom_plane() is" failed to apply to 6.12-stable tree

The patch below does not apply to the 6.12-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]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x 000acb4ce7fb9feba3072ce468ad681f6585cd5d
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026080541-difficult-synthetic-599f@gregkh' --subject-prefix 'PATCH 6.12.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

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

From 000acb4ce7fb9feba3072ce468ad681f6585cd5d Mon Sep 17 00:00:00 2001
From: Alex Deucher <[email protected]>
Date: Mon, 16 Feb 2026 09:32:53 -0500
Subject: [PATCH] drm/amd/display: check if dml21_add_phantom_plane() is
 successful

Verify that the phantom plane was allocated to avoid a later
segfault.

Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4970
Fixes: 70839da63605 ("drm/amd/display: Add new DCN401 sources")
Reviewed-by: Dillon Varone <[email protected]>
Signed-off-by: Fangzhi Zuo <[email protected]>
Tested-by: Dan Wheeler <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
(cherry picked from commit 5adb54abe5a8e82cbff7f8806db30a5f4924329f)
Cc: [email protected]

diff --git a/drivers/gpu/drm/amd/display/dc/dml2_0/dml21/dml21_utils.c b/drivers/gpu/drm/amd/display/dc/dml2_0/dml21/dml21_utils.c
index 835fece1d46a..50e445275b14 100644
--- a/drivers/gpu/drm/amd/display/dc/dml2_0/dml21/dml21_utils.c
+++ b/drivers/gpu/drm/amd/display/dc/dml2_0/dml21/dml21_utils.c
@@ -359,14 +359,13 @@ void dml21_handle_phantom_streams_planes(const struct dc *dc, struct dc_state *c
 					main_plane = main_stream_status->plane_states[dc_plane_index];
 
 					/* create phantom planes for subvp enabled plane */
-					dml21_add_phantom_plane(dml_ctx,
-							dc,
-							context,
-							phantom_stream,
-							main_plane,
-							&dml_ctx->v21.mode_programming.programming->plane_programming[dml_plane_index]);
-
-					phantoms_added = true;
+					if (dml21_add_phantom_plane(dml_ctx,
+								    dc,
+								    context,
+								    phantom_stream,
+								    main_plane,
+								    &dml_ctx->v21.mode_programming.programming->plane_programming[dml_plane_index]))
+						phantoms_added = true;
 				}
 			}
 		}