Prepare an interface for use.
int dev_open(struct net_device * dev);
dev
device to open
Takes a device from down to up state. The device's private open function is invoked and then the multicast lists are loaded. Finally the device is moved into the up state and a NETDEV_UP message is sent to the netdev notifier chain.
Calling this function on an active interface is a nop. On a failure a negative errno code is returned.