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I will relate a recent battle I had with a laptop that uses the Prism54 wireless chipset and runs Fedora 10. For quite some time, I could not get it to connect to a WPA protected network. With an open network, it would connect just fine. I didn’t bother with WEP. I wanted to find out what was causing it to fail with WPA.

This is an older eRacks CENTRINO laptop (Pentium M 1.6ghz, 1GB RAM and an 80GB hard drive.) This post will also hopefully help anyone else who has a laptop with the Prism54 chipset (mine specifically is a PrismGT mini-pci card.) Note that Prism54 is also available in PCI and USB wireless devices.

At first, I thought it might be a problem with the GNOME NetworkManager.  So, I tried other methods of connecting, such as using the command line (for iwconfig/ifconfig), wicd, Wireless Assistant and WiFi Radar. Some of these seem to work better than others, but again, none would allow me to connect to my WPA protected network at home. Thus, it was time to dig deeper.

After some sifting through forum posts, blogs, and bugzilla, I finally came across something that might help. Apparently, the prism54 drivers have several different modules that are loaded. For some reason, there is a module (prism54), which might be an older version of the complete set, and then there are other separate ones: p54common, p54pci and p54usb. So in my case, it was loading prism54, p54common, and p54pci. According to what I have read, the prism54 module causes conflicts with the newer p54common and p54pci set. The suggestion for now is to add prism54 to the module blacklist, located in /etc/modprobe.d/blacklist. You add the following entry at the bottom:

blacklist prism54

Once I did this and restarted networking, I could connect to my WPA-protected network using the default GNOME NetworkManager. All is well again in WiFi land.

Hopefully, this little jaunt with prism54 will be able to help someone else.

March 13th, 2009

Posted In: How-To, Laptop cookbooks

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