static int __device_attach_driver(struct device_driver *drv, void *_data)
{
	struct device_attach_data *data = _data;
	struct device *dev = data->dev;
	bool async_allowed;
	int ret;

	ret = driver_match_device(drv, dev);
	if (ret == 0) {
		/* no match */
		return 0;
	} else if (ret == -EPROBE_DEFER) {
		dev_dbg(dev, "Device match requests probe deferral\n");
		driver_deferred_probe_add(dev);
	} else if (ret < 0) {
		dev_dbg(dev, "Bus failed to match device: %d\n", ret);
		return ret;
	} /* ret > 0 means positive match */

	async_allowed = driver_allows_async_probing(drv);

	if (async_allowed)
		data->have_async = true;

	if (data->check_async && async_allowed != data->want_async)
		return 0;

	return driver_probe_device(drv, dev);
}
static int __device_attach_driver(struct device_driver *drv, void *_data)
{
	struct device_attach_data *data = _data;
	struct device *dev = data->dev;
	bool async_allowed;
	int ret;

	ret = driver_match_device(drv, dev);
	if (ret == 0) {
		 
		return 0;
	} else if (ret == -EPROBE_DEFER) {
		dev_dbg(dev, "Device match requests probe deferral\n");
		driver_deferred_probe_add(dev);
	} else if (ret < 0) {
		dev_dbg(dev, "Bus failed to match device: %d\n", ret);
		return ret;
	}  

	async_allowed = driver_allows_async_probing(drv);

	if (async_allowed)
		data->have_async = true;

	if (data->check_async && async_allowed != data->want_async)
		return 0;

	return driver_probe_device(drv, dev);
}