how to update atheros ath9k.ko driver to the latest on ubuntu linux

Download the latest compat-wireless-2.6.tar.bz2 from :
http://linuxwireless.org/en/users/Download
open it and :

find . -name "*" -exec touch {} \;
make
sudo -s
make install

modinfo ath9k
filename:       /lib/modules/2.6.28-15-generic/kernel/drivers/net/wireless/ath9k/ath9k.ko
...
mv /lib/modules/2.6.28-15-generic/kernel/drivers/net/wireless/ath9k/ath9k.ko /lib/modules/2.6.28-15-generic/kernel/drivers/net/wireless/ath9k/ath9k.ko.bak

make unload

cat > ~/wifi_reset.sh
#!/bin/bash -x
sudo modprobe -vr ath9k
sudo modprobe -vr ath5k
sleep 1
sudo modprobe -v ath9k
#sudo modprobe -v ath9k btcoex_enable=1
#sudo modprobe -v ath5k
sudo iwconfig wlan0 power off

#sudo iwconfig wlan0 rate 48M auto
#sudo iwconfig wlan0 txpower off
#sudo iwconfig wlan0 txpower auto
#sudo iwconfig wlan0 txpower 20dBm
sudo iwconfig wlan0 txpower 19dBm
<ctrl>-d

chmod +x ./wifi_reset.sh
./wifi_reset.sh