static int device_check_offline(struct device *dev, void *not_used)
{
	int ret;

	ret = device_for_each_child(dev, NULL, device_check_offline);
	if (ret)
		return ret;

	return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
}
static int device_check_offline(struct device *dev, void *not_used)
{
	int ret;

	ret = device_for_each_child(dev, NULL, device_check_offline);
	if (ret)
		return ret;

	return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
}