drm/imx: ipuv3-plane: Access old u/vbo properly in ->atomic_check for YU12/YV12

commit e73aca5184ad9fc948ba22b4d35dce11db35bb25 upstream.

Before accessing the u/v offset(aka, u/vbo for IPUv3) of the old plane state's
relevant fb, we should make sure the fb is in YU12 or YV12 pixel format(which
are the two YUV pixel formats we support only), otherwise, we are likely to
trigger BUG_ON() in drm_plane_state_to_u/vbo() since the fb's pixel format is
probably not YU12 or YV12.

Link: https://bugs.freedesktop.org/show_bug.cgi?id=98150
Fixes: c6c1f9bc798b ("drm/imx: Add active plane reconfiguration support")
Signed-off-by: Liu Ying <gnuiyl@gmail.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/imx/ipuv3-plane.c b/drivers/gpu/drm/imx/ipuv3-plane.c
index 9ca573915a81c68f4111066b3ecac7786b9acf71..927c51e8abc660cfd498aff0e64544ea78fada3b 100644 (file)
--- a/drivers/gpu/drm/imx/ipuv3-plane.c
+++ b/drivers/gpu/drm/imx/ipuv3-plane.c
@@ -360,7 +360,9 @@ static int ipu_plane_atomic_check(struct drm_plane *plane,
                if ((ubo > 0xfffff8) || (vbo > 0xfffff8))
                        return -EINVAL;
 
-               if (old_fb) {
+               if (old_fb &&
+                   (old_fb->pixel_format == DRM_FORMAT_YUV420 ||
+                    old_fb->pixel_format == DRM_FORMAT_YVU420)) {
                        old_ubo = drm_plane_state_to_ubo(old_state);
                        old_vbo = drm_plane_state_to_vbo(old_state);
                        if (ubo != old_ubo || vbo != old_vbo)