FAILED: patch "[PATCH] drm/atomic: Initialize variables in" failed to apply to 4.14-stable tree

FAILED: patch "[PATCH] drm/atomic: Initialize variables in" failed to apply to 4.14-stable tree

[gregkh]

The patch below does not apply to the 4.14-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 <stable@vger.kernel.org>.

thanks,

greg k-h

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

>From de2d8db395c32d121d02871819444b631f73e0b6 Mon Sep 17 00:00:00 2001
From: Boris Brezillon <boris.brezillon@bootlin.com>
Date: Tue, 24 Jul 2018 15:33:00 +0200
Subject: [PATCH] drm/atomic: Initialize variables in
 drm_atomic_helper_async_check() to make gcc happy

drm_atomic_helper_async_check() declares the plane, old_plane_state and
new_plane_state variables to iterate over all planes of the atomic
state and make sure only one plane is enabled.

Unfortunately gcc is not smart enough to figure out that the check on
n_planes is enough to guarantee that plane, new_plane_state and
old_plane_state are initialized.

Explicitly initialize those variables to NULL to make gcc happy.

Fixes: fef9df8b5945 ("drm/atomic: initial support for asynchronous plane update")
Cc: <stable@vger.kernel.org>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180724133300.32023-1-boris.brezillon@bootlin.com

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index ff858b890045..81e32199d3ef 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -1510,8 +1510,9 @@ int drm_atomic_helper_async_check(struct drm_device *dev,
 {
 	struct drm_crtc *crtc;
 	struct drm_crtc_state *crtc_state;
-	struct drm_plane *plane;
-	struct drm_plane_state *old_plane_state, *new_plane_state;
+	struct drm_plane *plane = NULL;
+	struct drm_plane_state *old_plane_state = NULL;
+	struct drm_plane_state *new_plane_state = NULL;
 	const struct drm_plane_helper_funcs *funcs;
 	int i, n_planes = 0;