Ubuntu – no wireless 12.04

broadcom

Its not an ungenerous statement that you are not alone with Broadcom issues.

Ubuntu does try its best by offering you what it thinks is the best driver.

I would advise you should stick with the STA driver offered to you for Natty (11.04) for this wireless card.

acer & kernel diagnosis

For the Natty (11.04) kernel there is a particular issue with Broadcom kernel driver clashing with the acer-wmi kernel module.

To test if you are suffering with this issue, run the following:

rfkill list all

solution

If the output from rfkill list all says it is "acer-wireless: soft blocked: yes" then run the following:

sudo modprobe -r acer-wmi
cd /etc/modprobe.d
sudo vi blacklist.conf

Then add blacklist acer-wmi as a new line at the end of the file.

What this does is hide from the kernel the visibility of the acer-wmi kernel module. Don't worry too much, this module has now power implications.

When you reboot - your wireless will be correctly recognised.

source

Same problem here, on a fresh (not upgraded) 12.04 system. If this is of any relevance, the computer is a "DELL Latitude E4300" and the Wifi card is a "Broadcom Corporation BCM4322".

The problem was solved by changing the router channel from 12 to 3. (Intriguingly channel 7, which was my first pick, did not seem to work either...)