Hi, On Wed, Jun 8, 2022 at 2:48 AM Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx> wrote: > > @@ -269,6 +280,31 @@ void drm_panel_bridge_remove(struct drm_bridge *bridge) > } > EXPORT_SYMBOL(drm_panel_bridge_remove); > > +/** > + * drm_panel_bridge_set_orientation - Set the connector's panel orientation > + * if the bridge is a panel bridge. > + * > + * @connector: The connector to be set panel orientation. > + * @bridge: The drm_bridge to be transformed to panel bridge. Ideally you should have a kernel doc to describe what you're returning. > + */ > +int drm_panel_bridge_set_orientation(struct drm_connector *connector, > + struct drm_bridge *bridge) > +{ > + struct panel_bridge *panel_bridge; > + > + if (!bridge) > + return 0; > + > + if (bridge->funcs != &panel_bridge_bridge_funcs) > + return 0; nit: Why do you need to handle NULL bridge and the case that someone calls you with something other than a panel-bridge? I'm not convinced that's useful. In general kernel style doesn't do massive validation of parameters unless there's a reason for it. ...if we do need to handle them then it feels like they should be returning -EINVAL or something, not 0. > @@ -917,10 +917,13 @@ void drm_bridge_hpd_notify(struct drm_bridge *bridge, > enum drm_connector_status status); > > #ifdef CONFIG_DRM_PANEL_BRIDGE > +bool drm_bridge_is_panel(const struct drm_bridge *bridge); > struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel); > struct drm_bridge *drm_panel_bridge_add_typed(struct drm_panel *panel, > u32 connector_type); > void drm_panel_bridge_remove(struct drm_bridge *bridge); > +int drm_panel_bridge_set_orientation(struct drm_connector *connector, > + struct drm_bridge *bridge); I suspect that you need some dummy versions of your new functions defined if "CONFIG_DRM_PANEL_BRIDGE" is not defined. Otherwise we're going to be yelled at by the kernel robot eventually. -Doug