[ath9k-devel] ath9k: set 5/10 MHz supported channels

[Simon Wunderlich <sw@simonwunderlich.de>]

Kamran,

> I have an AP with  AR9160 tunning openWRT. When I set chennel to 10MHz from
> debugfs entry. I can still connect it with other boards running OpenWrt.
> But from computers running latest linux kernel it was visible in scan when
> I was using AR5416 but I was not able to connect to my AP.
> Then I changed NIC to Atheros AR9227 based card not I can even see openwrt
> AP with 10MHz channel.

Please note that the OpenWRT and the mainline Linux implementation of 5/10 MHz 
are different. In Linux we have a limited but (hopefully) standard-conforming 
implementation, that means that also bitrates are interpreted for their 
respective frequencies. For example on mainline LInux in 5 MHz mode you have 
OFDM bitrates of 1.5, 2.25, 3, 4.5 Mbit/s etc what would be 6, 9, 12, 18 
Mbit/s on 20 MHz. OpenWRT will just announce the 20 MHz bitrates even on 5 MHz 
(it's more of a hack). This will likely confuse the Linux clients. There might 
also be other knobs not complete, as I said I've only tested the IBSS mode.

For the record I tested AR9220 and AR5213 in 5 and 10 MHz mode and after some 
timing corrections (patches have been merged upstream) this worked quite well.

I'd recommend to use only the same implementation together.

Cheers,
    Simon