drm/tegra: hub: Fix dereference before check

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

diff --git a/drivers/gpu/drm/tegra/hub.c b/drivers/gpu/drm/tegra/hub.c
index ba9b3cf..b3436c2 100644 (file)
--- 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