What happens after netdev_open?

I'm trying to understand a wireless lin开发者_开发问答ux device driver.

So after netdev_open is called...

what happens?

I know packets are being transmitted through an xmit function, but how does the code get there?

The dev->hard_start_xmit() function for the netdev is called out of the networking core - see net/core/dev.c (in particular dev_hard_start_xmit() and dev_queue_xmit()). These functions are in turn called out from the protocol handlers - see for example ip_queue_xmit() in net/ipv4/ip_output.c.