back out my change to ieee80211_crypto_encap that made it free its
mbuf argument on error. I had thought it was a bug. It was not.
It's the drivers that are broken. Make an(4), atw(4), ipw(4),
iwi(4), ral(4), rtw(4), ural(4), and wi(4) free the mbuf when
ieee80211_crypto_encap returns NULL. Also, return ath(4) to the
way it was---i.e., free the mbuf.
Thanks to Sam Leffler to pointing out my mistake.
Make the transmit section reserve one descriptor for issuing a
command at all times. If either transmit descriptors run out, or
header/buffer software descriptors run out, set IFF_OACTIVE and
get out of ipw_start, rather than re-using a descriptor or trying
to use a NULL descriptor that comes off the front of an empty
descriptor tailqueue.
This ought to fix port-i386/27439 and kern/28683.
dyoung