This change updates the old_fb pointer only after acquiring the plane lock, if there are no properties the fb cannot have been changed either, so this works out correctly.
Found in a discussion with Rob Clark. Cc: Rob Clark <robdclark at gmail.com> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com> --- drivers/gpu/drm/drm_atomic.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c index f6f2fb58eb37..bd7f723c708e 100644 --- a/drivers/gpu/drm/drm_atomic.c +++ b/drivers/gpu/drm/drm_atomic.c @@ -1472,12 +1472,6 @@ retry: goto fail; } - if (obj->type == DRM_MODE_OBJECT_PLANE) { - plane = obj_to_plane(obj); - plane_mask |= (1 << drm_plane_index(plane)); - plane->old_fb = plane->fb; - } - if (get_user(count_props, count_props_ptr + copied_objs)) { ret = -EFAULT; goto fail; @@ -1514,6 +1508,12 @@ retry: copied_props++; } + + if (obj->type == DRM_MODE_OBJECT_PLANE && count_props) { + plane = obj_to_plane(obj); + plane_mask |= (1 << drm_plane_index(plane)); + plane->old_fb = plane->fb; + } } if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT) { -- 2.1.0