K 10
svn:author
V 6
adrian
K 8
svn:date
V 27
2011-08-12T09:18:02.267715Z
K 7
svn:log
V 1327
Commit some (very untested) initial code to clean up after
a DELBA.

Once a DELBA is received, there may be:

* packets in the software TX TID queue
* packets in the hardware queue (aggregate or individual frames)

The software TX queue is fine - those packets don't yet have a
personality as they haven't been "scheduled".

The packets in the hardware TX queues need to be completed or
deleted.

So the logic here is:

* packets in the SWQ which are retries are discarded;
* packets in the SWQ which aren't retries are modified to have their
  completion handler be the default, non-aggregate one
* if there are any packets left in the hardware queue,
  mark the TID as "cleanup" and keep track of how many are outstanding
* if the TID is "cleanup", pause the TID so no further traffic
  is scheduled.

Then, when the packets are completed, the "incomplete" packet count
is updated and when it hits 0 (ie, all packets on the hardware queue)
it'll be unpaused and will begin running as a non-aggregate TID.

To avoid races, pause the TID in the addba handler before disabling the
addba state and calling ath_tx_cleanup(). Since the TXQ lock is held for
the duration of queue operations, any packets that snuck in before
the TID was paused will be downgraded to non-aggregate status by
ath_tx_cleanup().

Obtained from:	Atheros

END