From: Eric Dumazet <redacted>
Date: Tue, 01 Sep 2009 09:39:47 +0200

I was wondering if we could add a third parameter to 
ndo_start_xmit() (and pass the struct netdev_queue *txq)
in a smooth way, but could not find a solution.

Don't think that others didn't think about this too :-)

Unconverted drivers would not care of this third param; but this
should be provided by callers (like dev_hard_start_xmit())

Most multiqueue drivers have to recompute it, and even monoqueue drivers
have to call netif_stop_queue(dev)/netif_queue_stopped(dev), all
using netdev_get_tx_queue(dev, 0) in the end...

At least that is a constant structure offset reference, and thus
computed at compile time.

Anyways, I like Stephen's netdev_tx_t changes and I'm build testing
them now in my net-next-2.6