drm/layerscape: fix handling fsl_dcu_drm_plane_index result

The function can return negative value.

The problem has been detected using proposed semantic patch
scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci [1].

[1]: http://permalink.gmane.org/gmane.linux.kernel/2038576

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c
index 82be6b86a1686d20e6e46000b4bc5a2246cbddd4..d1e300dcd544a7cad7eb115849b307a6b73a7867 100644 (file)
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c
@@ -58,7 +58,8 @@ static void fsl_dcu_drm_plane_atomic_disable(struct drm_plane *plane,
                                             struct drm_plane_state *old_state)
 {
        struct fsl_dcu_drm_device *fsl_dev = plane->dev->dev_private;
-       unsigned int index, value, ret;
+       unsigned int value;
+       int index, ret;
 
        index = fsl_dcu_drm_plane_index(plane);
        if (index < 0)