Madwifi installed, ath0 gone

JimBass · 08-13-2007, 10:51 PM

Greetings everybody. I'm having some problems with madwifi on a friend's laptop, and I'd like to get some opinions on what is wrong.

So my friend bought a new laptop, and bravely allowed only Ubuntu 7 to be installed on it. I was given remote SSH access to the machine, in hopes that I could get the wireless working.

I got on, and found a standard atheros wireless card -

Code:

lspci
08:04.0 Ethernet controller: Atheros Communications, Inc. AR5005G 802.11abg NIC (rev 01)

Code:

uname -a
Linux mollypants 2.6.20-16-generic #2 SMP Thu Jun 7 20:19:32 UTC 2007 i686 GNU/Linux

So I downloaded madwifi 0.9.3.1 from sourceforge, compiled and installed it without issue. The wireless interfaces ath0 and wifi0 showed up, and behaved exactly as one would expect. I was able to associate the laptop wirelessly to the WEP protected network.

2 days later I received the phonecall that said, "I'm at a coffee shop, and I can't get online." When they took the laptop home so I could again SSH in, I was troubled to see this:

Code:

sudo iwlist scan
lo        Interface doesn't support scanning.

eth0      Interface doesn't support scanning.

Odd I thought, where did ath0 and/or wifi0 go. I assumed either the reboot hadn't loaded the madwifi modules to the kernel, but this shows that isn't the case:

Code:

lsmod |grep ath
ath_pci                97184  0
ath_hal               192592  1 ath_pci
wlan                  204100  1 ath_pci

Here's /etc/network/interfaces:

Code:

auto lo
iface lo inet loopback

auto eth1
iface eth1 inet dhcp

auto eth2
iface eth2 inet dhcp

auto ath0
iface ath0 inet dhcp
        wireless-essid 7007-1
        wireless-key hidden_obviously

auto wlan0
iface wlan0 inet dhcp

I've done the windows solution of rebooting, I've pulled out the ath_pci and ath_hal modules, put them back in, but it makes no difference. I've done make uninstall and make clean in /usr/local/madwifi, installed the brand new svn version of madwifi, that failed to compile, so I installed version 0.9.3.1 again. It was working flawlessly, and then somehow, the ability to use the built in wireless fails.

Code:

sudo iwconfig ath0 essid any
Error for wireless request "Set ESSID" (8B1A) :
    SET failed on device ath0 ; No such device.

sudo iwconfig wifi0 essid any
Error for wireless request "Set ESSID" (8B1A) :
    SET failed on device wifi0 ; No such device.

I'm hoping somebody here can point me in the right direction to get this working. If you need any additional info, I'll be glad to provide it.

Peace,
JimBass

dracolich · 08-14-2007, 09:47 AM

Did dmesg indicate anything? Is it possible the switch or key had been toggled to turn it off?

JimBass · 08-14-2007, 10:10 AM

The command "dmesg|grep ath" and "dmesg |grep wifi" show nothing. Reading the full output of dmesg didn't turn anything up either. I have never actually seen the laptop itself, it is in Maryland and I'm in NYC. I'll ask the owners if they see a toggle switch. Its been my experience that laptops don't generally have a toggle on/off switch, but as I said, I've never actually seen the laptop to confirm that. I'll ask and post back.

It does seem like something has been switched off.

Peace,
JimBass

dracolich · 08-14-2007, 10:32 AM

Every wireless-capable laptop I've seen has either a button/switch on one side, or a Fn key combination to turn the wireless on or off. It's indicated with a symbol that looks like an antenna with waves on the sides. In the case of the keys the symbol is printed on the key face.

JimBass · 08-14-2007, 09:06 PM

Problem solved. It did seem to be a combination of a toggle switch that may have been hit during the lid opening/closing process, as the toggle switch is under the main lid switch. Genius design on Acer's part. In any case, on the modules front, there is an additional apparently important module named ath_rate_sample.

Now the output of lsmod | grep ath looks like this:

Code:

 lsmod |grep ath
ath_rate_sample        13952  1
ath_pci                97184  0
wlan                  204100  5 wlan_wep,wlan_scan_sta,ath_rate_sample,ath_pci
ath_hal               192592  3 ath_rate_sample,ath_pci

So it may even be possible that if I had just modprobed ath_rate_sample, it may have worked.

In any case, it is now cool. Thanks to all for the input.

Peace,
JimBass