On my machine suddenly wireless stopped working and the machine in problem started showing following output for lspci -vnn (output edited)
30:00.0 Network controller: Broadcom Corporation BCM4311 802.11a/b/g (rev 01)
Capabilities:  Power Management version 2
Capabilities:  MSI: Enable- Count=1/1 Maskable- 64bit-
Capabilities: [d0] Express Legacy Endpoint, MSI 00
Capabilities:  Advanced Error Reporting
Capabilities: [13c] Virtual Channel
Kernel driver in use: b43-pci-bridge
Kernel modules: ssb
$ sudo lspci -nn
30:00.0 Network controller : Broadcom Corporation BCM4311 802.11a/b/g [14e4:4312] (rev 01)
I am going to install the correct driver for this wireless card. Then I will remove the “incorrect” driver (bcmwl) which Ubuntu installed by default.
$ sudo apt-get update
$ sudo apt-get install firmware-b43-installer
$ sudo apt-get remove bcmwl-kernel-source
$ sudo reboot
You basically need 2 things
a copy of the b43 firmware folder, which just needs to be placed in
Download and extract the folder b43 and place it in /lib/firmware
If a folder b43 already is there, just delete it.
It's always possible b43 won't work, but it should.
Worth a shot, you can always switch back to 'wl'