Configure Atheros AR9285 wireless in Gentoo
I got the solution on Gentoo Forums. It turned out to be a mis-configured kernel.
Here is the kernel configuration that works (from the post that I linked to above):
[*] Networking support --->
-*- Wireless --->
<*> cfg80211 - wireless configuration API
[*] enable powersave by default
[*] cfg80211 wireless extensions compatibility
[*] Wireless extensions sysfs files
<*> Common routines for IEEE802.11 drivers
<*> Generic IEEE 802.11 Networking Stack (mac80211)
Default rate control algorithm (Minstrel) --->
-*- Enable LED triggers
Device Drivers --->
[*] Network device support --->
[*] Wireless LAN --->
<*> Atheros Wireless Cards --->
<*> Atheros 802.11n wireless cards support