Welcome, this is Dr. Cu.

Lonely in the Dessert.

Wireless Failure After Upgrading Ubuntu on a Macbook Air

It feels really nasty when you find the wireless down after rebooting from an upgrade. A simple command will secure the situation by reverting back to the original driver. A lesson from this is: never touch the wireless driver especially when your laptop has only one network card to use.

sudo modprobe brcmsmac