issues with the recent ath commits (r227740, r227651, ...)

[Alexander Best]

hi there,

after the recent ath commits (r227740, r227651, ...) i'm experiencing issues
with my

ath0 at pci0:5:1:0:	class=0x020000 card=0x5a001385 chip=0x0013168c rev=0x01 hdr=0x00
    vendor     = 'Atheros Communications Inc.'
    device     = 'AR5212/AR5213 Wireless Network Adapter'
    class      = network
    subclass   = ethernet

card on amd64. my system will either panic right during boot up or will
actually boot, but then after a few minutes lock up my whole system.

i'll try reverting my kernel to r227739 to check, if that fixes the issue.
if it does, i'll try to gather some more stats to identify the issue more
thoroughly. if it does not, i'll try reverting past the other recent ath
commits (such as r227651).

cheers.
alex