extern void unregister_dock_notifier(struct notifier_block *nb);
extern int register_hotplug_dock_device(acpi_handle handle,
const struct acpi_dock_ops *ops,
extern void unregister_dock_notifier(struct notifier_block *nb);
extern int register_hotplug_dock_device(acpi_handle handle,
const struct acpi_dock_ops *ops,