2.0 KiB
| title | layout | created | updated | toc | tags | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| WiFi on the Acer Aspire One | default | 2008-10-21 00:14:48 +0200 | 2009-09-14 18:48:23 +0200 | false |
|
Chipset: Atheros AR2425
Change Regdomain
The WiFi card comes set to regdom 0x65 (World/ETSI C) which limits the channels to 1..11. (iw list shows
channels 12..14 as disabled.) In Germany, there are also channels 12 and 13 which are unusable this way. But
there's the tool ath_info which can read and write the EEPROM on the card and thus also the regdomain.
First, find the base address of the adapter using
lspci -vv
Mine was at address 75200000. Now you can dump the contents of the EEPROM using
ath_info 0x75200000
To write the EEPROM, you have to unlock it by setting a GPIO register, namely the first, to zero. I changed the
regdomain to 0x00 (=ALL channels available) 0x68 (=EU1 World) using this command:
ath_info -g 1:0 -w 0x75200000 regdomain 68
You can find all valid codes by looking at the DMN_ constants in the
regdom.h file.
After unloading the modules: ath5k, ath, mac80211 and cfg80211 and doing a modprobe ath5k, the command
iw list should show the two new channels enabled.
For older ieee80211 modules, there's a module option ieee80211_regdom for the cfg80211 module. This takes
the values US, JP or EU. Add the following lines to /etc/modprobe.d/options:
options cfg80211 ieee80211_regdom=EU
options lbm_cw_cfg80211 ieee80211_regdom=EU
And after a reboot, you will have channels 12 and 13 available.
On Jaunty, you have to install the package iw and use the following command in e.g. your /etc/rc.local to set
the regdomain to Germany:
iw reg set DE
Possible errors
If you get the message MAC revision 0xffff is not supported! it means that some other module, likely ath_hal
and/or ath_pci took over your card.