Comment 0 for bug 762987

I'm using a D-Link DWA 140 USB WLAN stick which worked fine under Maverick. On Natty the NetworkManager displays "firmware missing", connecting to an access point is not possible. This is not only occuring under Natty, it also doesn't work with Maverick if you install the 2.6.38 mainline kernel.

There is a workaround for this problem. A quick "lsmod | grep rt" shows the following:

parport_pc 36959 0
parport 46458 3 parport_pc,ppdev,lp
rt2870sta 450556 0
rt2800usb 18235 0
rt2800lib 45181 1 rt2800usb
crc_ccitt 12667 2 rt2870sta,rt2800lib
rt2x00usb 20330 1 rt2800usb
rt2x00lib 49235 3 rt2800usb,rt2800lib,rt2x00usb
mac80211 294370 3 rt2800lib,rt2x00usb,rt2x00lib
cfg80211 178528 2 rt2x00lib,mac80211

rt2870sta is the right module which is also loaded in Maverick/2.6.35 and which is needed for the stick to work. rt2800usb, rt2800lib, rt2x00usb and rt2x00lib are wrong modules which are causing the problem. So we have to unload all the ralink-related modules:

sudo modprobe -rf rt2870sta rt2800usb rt2800lib rt2x00usb rt2x00lib

Then we can load the right module:

sudo modprobe rt2870sta

INow it should be possible to connect to an access point with the network manager. To make this change permanent, we have to blacklist all the wrong modules in the /etc/modprobe.d/blacklist.conf file.

It would be awesome if the developers fix this until natty release so its working out-of-the-box. :-)