/* write_undock - write method for "undock" file in sysfs  */
static ssize_t write_undock(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
/* write_undock - write method for "undock" file in sysfs  */
static ssize_t write_undock(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	int ret;
	struct dock_station *dock_station = dev->platform_data;
	if (!count)
		return -EINVAL;
	begin_undock(dock_station);
	ret = handle_eject_request(dock_station, ACPI_NOTIFY_EJECT_REQUEST);
	return ret ? ret: count;
}