From 7cf77b273a8fc51e7de622fa6691abd4436a9a6b Mon Sep 17 00:00:00 2001
From: Thierry Reding <treding@nvidia.com>
Date: Mon, 11 Feb 2019 11:51:20 +0100
Subject: [PATCH] drm/tegra: hub: Fix dereference before check
Git-commit: 7cf77b273a8fc51e7de622fa6691abd4436a9a6b
Patch-mainline: v5.1-rc3
References: bsc#1111666

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/tegra/hub.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/tegra/hub.c b/drivers/gpu/drm/tegra/hub.c
index ba9b3cfb8c3d..b3436c2aed68 100644
--- a/drivers/gpu/drm/tegra/hub.c
+++ b/drivers/gpu/drm/tegra/hub.c
@@ -378,14 +378,16 @@ static int tegra_shared_plane_atomic_check(struct drm_plane *plane,
 static void tegra_shared_plane_atomic_disable(struct drm_plane *plane,
 					      struct drm_plane_state *old_state)
 {
-	struct tegra_dc *dc = to_tegra_dc(old_state->crtc);
 	struct tegra_plane *p = to_tegra_plane(plane);
+	struct tegra_dc *dc;
 	u32 value;
 
 	/* rien ne va plus */
 	if (!old_state || !old_state->crtc)
 		return;
 
+	dc = to_tegra_dc(old_state->crtc);
+
 	/*
 	 * XXX Legacy helpers seem to sometimes call ->atomic_disable() even
 	 * on planes that are already disabled. Make sure we fallback to the
-- 
2.16.4