K 10
svn:author
V 6
adrian
K 8
svn:date
V 27
2013-02-25T10:30:25.790421Z
K 7
svn:log
V 870
Introduce a new net80211 TX IC lock, to serialise both the VAP and
the IC frame processing.

This is a temporary(ish) thing, mostly to get the TX handling "correct"
for now.

The overview:

* The TX IC lock is grabbed before any vap or raw xmit calls occur that
  invoke the 802.11 setup path;
* it explicitly occurs _before_ fast frame queuing and ampdu handling -
  + the ff queuing may or may not pair it with a second frame, and go
    through the encap path;
  + the ampdu path can actually send a management frame at this point,
    so this avoids a recursive call.
* modify iwn and ath TX path to grab the net80211 TX lock if the driver
  TX start path is called deferred - eg, during reset, or TX completion.
  This ensures that the same locking is done and in the same order.

It's inefficient but hopefully (!) correct enough to stop all of the
subtle races..

END