This howto derived from this thread.
Similar thread can be found here. Haven't compared but that thread has two posts w/ verified working driver following those instructions.
Homepage for the rt2570 driver can be found here.
This link shows a list of devices reported by users to work with the rt2xxx drivers. Which the rt2570 section shows the dwl-g122 as working with this driver. I've seen quite a few posts lately about getting this device to work. Post your results and success stories for others to see.
If not installed already, these packages need to be installed.
At the time this was written driver was rt2570-1.1.0-b1. If driver is updated commands will need to change to that file name.
sudo apt-get install build-essential linux-headers-`uname -r` gcc-3.4
Step 1 Download and untar file
Go here and choose the rt2570beta driver. You'll get a choice of mirrors where to download from. Save it to file.
Now copy the file to /usr/src
Move to /usr/src
sudo cp /path/to/file/rt2570-1.1.0-b1.tar.gz /usr/src/
Move into file
sudo tar -xzvf rt2570-1.1.0-b1.tar.gz
Step 2 Make and install file
Step 3 Set up and load module
make a directory for the .ko file
copy file over to new directory
sudo mkdir /lib/modules/`uname -r`/drivers/
Then insert module into kernel
sudo cp /lib/modules/2.6.12/extra/rt2570.ko /lib/modules/`uname -r`/drivers/
Configure your wireless device through /etc/network/interfaces. Here is a sample file.
sudo insmod /lib/modules/`uname -r`/drivers/rt2570.ko
iface rausb0 inet dhcp
restart the networking service
sudo /etc/init.d/networking restart
Now try to bring up your device
To load module at boot add it to /etc/modules file
sudo ifconfig rausb0 up
sudo echo rt2570 >> /etc/modules
This driver is a beta driver and there are probably bugs. In /usr/src/rt2570-1.1.0-b1/Modules/ there is a file TESTING. Read this file as it gives information on logging and reporting bugs.