int usbnet_open (struct net_device *net)
{
	struct usbnet		*dev = netdev_priv(net);
	int			retval;
	struct driver_info	*info = dev->driver_info;

	if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
		netif_info(dev, ifup, dev->net,
			   "resumption fail (%d) usbnet usb-%s-%s, %s\n",
			   retval,
			   dev->udev->bus->bus_name,
			   dev->udev->devpath,
			   info->description);
		goto done_nopm;
	}

	if (info->reset && (retval = info->reset (dev)) < 0) {
		netif_info(dev, ifup, dev->net,
			   "open reset fail (%d) usbnet usb-%s-%s, %s\n",
			   retval,
			   dev->udev->bus->bus_name,
			   dev->udev->devpath,
			   info->description);
		goto done;
	}

	/* hard_mtu or rx_urb_size may change in reset() */
	usbnet_update_max_qlen(dev);

	if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
		netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
		goto done;
	}

	/* start any status interrupt transfer */
	if (dev->interrupt) {
		retval = usbnet_status_start(dev, GFP_KERNEL);
		if (retval < 0) {
			netif_err(dev, ifup, dev->net,
				  "intr submit %d\n", retval);
			goto done;
		}
	}

	set_bit(EVENT_DEV_OPEN, &dev->flags);
	netif_start_queue (net);
	netif_info(dev, ifup, dev->net,
		   "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
		   (int)RX_QLEN(dev), (int)TX_QLEN(dev),
		   dev->net->mtu,
		   (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
		   (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
		   (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
		   (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
		   (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
		   "simple");

	/* reset rx error state */
	dev->pkt_cnt = 0;
	dev->pkt_err = 0;
	clear_bit(EVENT_RX_KILL, &dev->flags);

	tasklet_schedule (&dev->bh);
	if (info->manage_power) {
		retval = info->manage_power(dev, 1);
		if (retval < 0) {
			retval = 0;
			set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
		} else {
			usb_autopm_put_interface(dev->intf);
		}
	}
	return retval;
done:
	usb_autopm_put_interface(dev->intf);
done_nopm:
	return retval;
}

Unknown