K 10
svn:author
V 6
adrian
K 8
svn:date
V 27
2011-08-18T09:18:39.412150Z
K 7
svn:log
V 2134
Flip on TX aggregate formation. No, it doesn't quite work.

* Push ath_tx_setds() and ath_tx_chaindesc() back to where I
  had it - ie, setup just before the buffer was queued to the
  hardware.

* Use the 11n aggregate form methods from Sam's HAL, rather than
  the added methods from linux/reference code. I'm still unsure
  which to use for now, but those methods do seem to work.
  the chaindesc method knows about sub-frames _and_ segments of
  a sub-frame; the Linux/reference code seem to assume that
  a TX'ed aggregate sub-frame will only take up one skb.
  (Or there's something else subtle going on that I haven't
  quite understood.)

* Modify ath_tx_form_aggr() to only form the aggregate buffer
  list; it doesn't link the descriptors together or do any
  descriptor setup.

* Write ath_tx_setds_11n() which sets up an aggregate descriptor
  set. This sets up the first/last descriptors as appropriate
  as well as chaining the subframes together.

* Teach the aggregate scheduler function to use
  ath_tx_form_aggr(), then based on the result of that process,
  either send a single-packet (which is known to be inside the
  BAW), or fire off an aggregate frame list to the hardware.

* Add some debugging to try and figure out what's going on.

As it stands, the TX path halts very quickly. It looks like
some completion handling is incorrect, as the TX stops because
the BAW tracking becomes out of whack. If I disable this (ie,
treat all packets as ACKed and not retry anything), TX is
slow (on the order of a few megabits/sec) but the hardware
doesn't lock up; so it's likely the descriptor fiddling is
functioning mostly correctly.

Unfortunately, I don't yet have a clear picture how I'm
supposed to setup multi-segment frames inside an aggregate.
As mentioned above, Linux/reference code both seem to assume
an aggregate subframe fits in a whole skb.

(Yes, the receive-side does indeed indicate the frames
received were A-MPDU frames. No, I haven't even begun to
dig deeply into the aggregate setup to see if I've done
everything completely correctly. No, don't expect to use
this in STA/Hostap mode just yet.)

END