drm/i915: hold mutex for unreference() in i915_gem_tiling.c

Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NEric Anholt <eric@anholt.net>
Signed-off-by: NDave Airlie <airlied@linux.ie>

drivers/gpu/drm/i915/i915_gem_tiling.c

@@ -299,9 +299,8 @@ i915_gem_set_tiling(struct drm_device *dev, void *data,
 	}
 	obj_priv->stride = args->stride;
 
-	mutex_unlock(&dev->struct_mutex);
-
 	drm_gem_object_unreference(obj);
+	mutex_unlock(&dev->struct_mutex);
 
 	return 0;
 }
@@ -340,9 +339,8 @@ i915_gem_get_tiling(struct drm_device *dev, void *data,
 		DRM_ERROR("unknown tiling mode\n");
 	}
 
-	mutex_unlock(&dev->struct_mutex);
-
 	drm_gem_object_unreference(obj);
+	mutex_unlock(&dev->struct_mutex);
 
 	return 0;
 }