WiFi on Ubuntu with the Sony Vaio VGN-FS415E

Last week a colleague wanted to clean up and reinstall his laptop and asked me if it was possible to configure the Windows installation in a way that keeps the maintenance effort low because the system was just supposed to provide a browser and a media player. I configured the new Windows installation according to his requirements and offered him to install Ubuntu too, so he could test both operating systems.

After the installation of Ubuntu all hardware components were successfully initialized, but no WiFi networks did show up although the internal WiFi card was reported active. Unfortunately the solution was not that obvious.

The Sony Vaio VGN-FS415E contains the following WiFi card manufactured by Atheros (lspci output):

Ethernet controller: Atheros Communications Inc. Atheros AR5001X+ Wireless Network Adapter (rev 01)

The output of dmesg provides the usual messages of the cfg80211 module and concludes with:

ADDRCONF(NETDEV_UP): wlan0: link is not ready

That is a somewhat hidden error in the ath5k-driver, which cannot handle the Atheros chip.

Personally, I thought that problems with Atheros chips would belong to the past since the ath5k- and ath9k-drivers have been introduced – but it seems that this specific chip falls through the cracks. So this is a case for the mawifi-driver, again.

This driver was not sent to retirement for nothing and accordingly was never accepted into upstream kernel because it contains proprietary parts. Unfortunately there is no package linux-restricted-modules-generic included in the current Ubuntu version 11.04 “Natty Narwhal” (which was used so far to install the madwifi-driver). Building the driver yourself has the disadvantage that all problems return with the next kernel update because it is not automatically rebuilt.
In addition the madwifi driver has another flaw: if you wake up your laptop from suspend mode you will realize that WiFi is not working anymore. The solution can be found in a discussion on a bug report on launchpad.net.

To practically resolve the issue we need a pice of software called “DKMS”. DKMS rebuilds drivers after a kernel update automatically. Ironically the last time I coped with this problem was in December 2008. A Google search for “madwifi dkms” comes up with this forum post written by me (!) in the ubuntuusers.de-Forum as the second hit. It is a bit funny that nothing has happened since that post.

Since I have not found anything adequate I have a decided to provide a DKMS package for madwifi in a PPA by myself.

At first you need to add my PPA:

$ sudo add-apt-repository ppa:mario-fischer/ppa
$ sudo apt-get update

Next you need to install the package madwifi-dkms:

$ sudo apt-get install madwifi-dkms

The package comes with the suspend problem fixed.

Have fun with it 🙂

Dieser Post ist auch verfügbar auf: German

This entry was posted in Uncategorized. Bookmark the permalink.

Leave a Reply

Your email address will not be published. Required fields are marked *