[RFC] serialising net80211 TX

[Adrian Chadd]

The (many) problems include the two TX paths - one is via _start /
_transmit, and one is the raw xmit path.

So in the short term it'll be easier (!) to just wrap all TX entry
points with a VAP TX lock.
Once that's done and we've debugged it, we can look at breaking it
into a queue with a taskqueue thread for deferred transmit.

How's that sound?


Adrian