If you have a Broadcom wireless chipset BCM4311, BCM4312, BCM4321, or BCM4322 it will not work with Ubuntu Karmic after an upgrade or an install.
To get it working, you need to install the STA driver. You can get it from the Broadcom site:
Follow the instructions in the README.txt file which is on same page.
After you have finished installing it the wireless will work, but only until the next reboot. To make this permanent follow these steps:
sudo rmmod ssb
For some reason you cannot blacklist the ssb module. It always runs on boot even if it is in the blacklist.conf file.
After that you need to run this to get rid of the ssb module permanently:
sudo update-initramfs -u
2. Now that we got rid of ssb, we need to make sure that lib80211 is loaded on boot. To do that add lib80211 to the end of the /etc/modules file:
echo "lib80211" | sudo tee -a /etc/modules
I went ahead and added wl to it as well:
echo "wl" | sudo tee -a /etc/modules
So the /etc/modules file looks like this:
# /etc/modules: kernel modules to load at boot time. # # This file contains the names of kernel modules that should be loaded # at boot time, one per line. Lines beginning with "#" are ignored. lp rtc lib80211 wl
3. Now we need to make sure that “insmod wl.ko” as specified in the README.txt file runs every time we boot. There might be a better way to do this but I just added it to the /etc/rc.local file.
Before I did this I copied the wl.ko file to the /lib/modules/2.6.31-14-generic/kernel/lib directory. This way we can get rid of the source files we downloaded from the Broadcom site along with the binaries we compiled and not worry about losing the wl.ko file:
sudo cp wl.ko /lib/modules/2.6.31-14-generic/kernel/lib
Then add the line “insmod /lib/modules/2.6.31-14-generic/kernel/lib/wl.ko” at the end of the rc.local file, right above the exit 0 line:
sudo gedit /etc/rc.local
Here is how the rc.local file looks:
cat /etc/rc.local #!/bin/sh -e # # rc.local # # This script is executed at the end of each multiuser runlevel. # Make sure that the script will "exit 0" on success or any other # value on error. # # In order to enable or disable this script just change the execution # bits. # # By default this script does nothing. insmod /lib/modules/2.6.31-14-generic/kernel/lib/wl.ko exit 0
4. Last step is to pin down the linux kernel so that we don’t upgrade the kernel accidentally along with the other updates:
System -> Administration -> Synaptic Package Manager
Then click on the “Status” button and select “Installed”. Then search for “linux-“. Select all packages that start with “linux-” and then Package -> Lock Version.