drm: omapdrm: if omap_plane_atomic_update fails, disable plane

omap_plane_atomic_update() calls dispc_ovl_setup(), which can fail (but
shouldn't). To make the code a bit more robust, make sure the plane gets
disabled if dispc_ovl_setup() fails, as otherwise we might get illegal
HW configuration leading to error interrupts.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

drivers/gpu/drm/omapdrm/omap_plane.c

@@ -132,8 +132,10 @@ static void omap_plane_atomic_update(struct drm_plane *plane,
 	/* and finally, update omapdss: */
 	ret = dispc_ovl_setup(omap_plane->id, &info, false,
 			      omap_crtc_timings(state->crtc), false);
-	if (WARN_ON(ret))
+	if (WARN_ON(ret)) {
+		dispc_ovl_enable(omap_plane->id, false);
 		return;
+	}
 
 	dispc_ovl_enable(omap_plane->id, true);
 }