For some reason I was experiencing wifi disconnects with the
ath9k wifi driver under Linux (Ubuntu 12.04). After reading numerous blogs and bug reports (disable ipv6, use
hwcrypto=0, etc.), I suspected it was the power management that was somehow disabling the driver, in turn leading to a disconnect. This will probably be fixed in newer kernels (Ubuntu 12.04 ships 3.2.x).
For now I took a shortcut and disabled the power management on the
wlan0 interface. For this to work I created a (super)small script:
#!/bin/sh -e case $IFACE in wlan0) /sbin/iwconfig "$IFACE" power off ;; esac