Re: [PATCH] mac80211 : fix a race with update_tkip_key

[gregor kowski <gregor.kowski@gmail.com>]

Race could happen with QOS :
let's consider queue 0 low prio and queue 1 high prio

- queue 1 send packet lot's of packet (iv32 = 0, iv32=1, iv32=2)
- queue 0 send a packet with iv32=1 and iv16=0xffff (or near wrap)

If queue 0 packet with iv32=1 is received after queue 1 with iv32=2, we will
- send tkip key for iv32=2 to hardware
- send tkip key for iv32=1 to hardware
and then we should wait wrap to iv32=3 to have a chance to send
correct key to hardware.


With this patch, we only send tkip key to hardware on the first wrap of a queue.
With the previous example, we will only send  tkip key for iv32=2 to hardware.

Gregor