I upgraded Ubuntu from 11.10 to 12.04, until which wireless was working just fine. After the upgrade and reboot, wireless is not even being detected (When I click the network manager icon in the top panel, it does not show the wireless networks. Neither the Enable wireless option is there). But my laptop's LED indicator shows wireless is on.
This is a Dell Vostro 3450 laptop with:
Broadcom Corporation BCM4313 802.11b/g/n Wireless LAN Controller (rev 01)** (from lspci). Is any other info needed?
How do I get Wifi working?