K 10
svn:author
V 6
adrian
K 8
svn:date
V 27
2011-09-05T00:10:37.463436Z
K 7
svn:log
V 1181
Migrate the rate control selection out from the packet setup code and
instead call it just before the packet is TXed.

For non-aggregate packets, call it just before the frame is queued
to hardware.

For aggregate packets, call it on the first frame in the aggregate
list so the aggregate code itself has a rate control selection to
use when building the aggregate.

This allows for some useful behaviour:

* rate selection is now not done per-frame when doing aggregation.
  Aggregation only requires a rate lookup for the first frame.
  The rest are ignored.

* The rate control module now gets a more "balanced" idea of how many
  times findrate is called versus completion. Beforehand, findrate
  would be called for each frame, but completion would be called for
  the entire aggregate.

* software retransmission now allows for a new rate lookup - that way
  the retransmits aren't done using the same failing rates.

This improves the aggregate throughput stability but it doesn't fix
things entirely - primarily because ath_rate_sample is still making
some very poor rate control decisions (eg dipping down to single-stream
rates and trying MCS14/15 when it doesn't work.)

END