K 10
svn:author
V 6
adrian
K 8
svn:date
V 27
2011-08-24T08:32:51.928691Z
K 7
svn:log
V 873
Fix a TX hang that crept in when I flipped in ATH_BUF_BUSY / TX buf cloning.
This was due to an ATH_BUF_BUSY buffer ending up at the head of the txbuf list,
causing ath_getbuf() to halt TX until the TX queue had caught up. Since the
TX queue wasn't -really- full, TX would stay paused.

The basic problem: because I just checked the busy flag, the:

* buffer would be cloned; the ATH_BUF_BUSY tagged buffer would be freed
  and tossed onto the end of the list;
* if the new cloned buffer (not busy) was already at max retries, the
  new non-busy buffer would be freed, and added to the end of the list;
  and thus the busy buffer isn't at the end of the list;
* .. and bewm. The flag would never be cleared.

Also, whilst I'm at it, add a comment about an error condition if the buffer
can't be cloned - i may end up confusing the DMA code a bit. I'll sort that
out later.

END