The ath5k driver in 2.6.28.6, 2.6.30.8, and the recent tip of
wireless-testing 2.6.32-rc2-wl-39303-g8e025fe occasionally causes
a system lockup/hang while the interface is being asked to
associate with WPA2 or WEP networks.  There are a number of ways
I've gone about reproducing this.

1.)  Cycle wpa_cli {disconnect,reassociate}
2.)  Cycle ifconfig {up,down}
3.)  Enter a nonexistent ssid
4.)  Enter an invalid key.

I've attached a serial console, but with EARLY_PRINTK on/off,
nothing is sent.  The SysRq commands do not work and acpid does
not recognize the power button.  It typically takes on the order
of hours for this condition to occur.


06:01.0 Ethernet controller: Atheros Communications, Inc. AR5005G 802.11abg NIC (rev 01)
net-wireless/wireless-tools-29
net-wireless/wpa_supplicant-0.5.7

I should also mention that I cannot reproduce this on older
hardware.  The current system is an Intel Q9400 (2.66GHz quad
core) with 8 GB of RAM, whereas the older system used two AMD
Opteron 265 HE (1.8GHz) with 4 GB of RAM.  I've been testing on
the older system for over a week without a single issue.  Across
six of the newer machines, I typically get at least three hanging
when left to run overnight.