Update 2013-02-27: This solution on Ask Ubuntu is much better, because it includes properly packaged things that should update when you upgrade Ubuntu.
Once again, I find that my Broadcom wireless card is not working. I don’t know how long this has been going on—I’m normally wired.
Mode of Failure
I have no wireless. Wireless is not displayed under Network Manager. My wireless card does not have an associated interface.
iwconfig shows this:
$ iwconfig lo no wireless extensions. eth0 no wireless extensions.
*-network UNCLAIMED for the wireless card.
I tried rebuilding the driver provided by Broadcom. The build succeeded, but
modprobe wl still failed like so:
$ sudo modprobe wl FATAL: Module wl not found. FATAL: Error running install command for wl
.ko file existed at the correct place:
$ locate wl.ko /lib/modules/3.0.0-12-generic/kernel/drivers/net/wireless/wl.ko . .
Finally, I found a solution here. By running
sudo depmod -a, I could then
sudo modprobe wl and my wireless started working again.
I don’t know if it was necessary for me to get the latest drivers from Broadcom or if the version Ubuntu packaged would have worked. But my wireless is working again now.