Cannot unload if_ath kernel module / machine does not shut down

[Andreas Lattka]

Hello All there,

I have got a shiny new Sony Vaio VGN-FS415E, installed FBSD6, (FreeBSD
6.0-RELEASE-p4). For wireless connection there is built in an Atheros
5212 chip. I configured the kernel conf file to include all the atheros
modules according to the man ath:

device	ath
device	ath_hal
device	ath_rate_onoe,

all works well until the machine is to be shutdown. When I enter halt
-p, or reboot, the machine starts to shut down, but stops, after the
uptime message is displayed. Nothing more happens, I have to manually
switch off the machine. The next time I switch on the machine, the oss
sound will crash the machine.

I did remember, that I had no problem to shut down the machine when the
ath modules were not used, so I cleared the ath modules from the kernel
conf file and did include if_ath into the loader.conf. Again, all is
going well until shutdown. Same bad behaviour. Then I tried to manually
unload the ath modules, only ath_rate module can be unloaded, ath_hal
gives device busy, and trying to unload the if_ath will freeze the
machine. I confirmed that the Atheros 5211 is working well, 5212 give
those problems.
Does anybody have any idea how to unload the if_ath module?

Thank you!

Andreas