There is a field, no_80211_encap, added to ieee80211_tx_info:control
to mark if the 802.11 encapsulation is offloaded to driver.

Why is that needed? Since you have a separate TX path (ndo_start_xmit),
wouldn't it make more sense to call into a drv_tx_8023() or something
like that instead?

There is also a new callback for tx completion status indication
to handle data frames using 802.11 encap offload.

Maybe you could just use _noskb?

Haven't really looked at the rest all that much, few comments:

 * not sure you're handling non-linear frames right, are you assuming
   the driver can handle them? probably a fair assumption, but should
   be documented
 * you seem to also be assuming that the driver not only does all
   encryption in HW (which is obviously needed) but also does all the
   key lookups etc. - also seems fair, but also should be documented
 * similarly for a lot of other (all?) fields in tx_info
 * you seem to be assuming that if encap offload is supported then it's
   also *desired* for AP/VLAN and client interfaces, if not 4-addr.
   This seems ... probably about right, but if drivers don't always
   support it? Or support it in more cases? Perhaps we can move the
   SUPPORTS_80211_ENCAP flag into a VIF flag instead, so they can do it
   more fine-grained?

johannes