#Overview The latest Ubuntu 15.04 announced it has already support OCB mode. its kernel version is 3.19.0, however,it just added ocb feature on mac80211 and nl80211 layer, for drvier layer, we have to menully patch it by ourself. Here will show how patch whole stack to suport OCB/802.11p for Kernel 3.19.0 and ath9k step by step.
#Get 3.19.0 source code from official site
If you are in ubuntu 15.04, just follow the steps below,
apt-get source linux-image-$(uname -r)
apt-get build-dep linux-image-$(uname -r)