Comment 14 for bug 929960

(In reply to comment #7)
> I got the source for xserver-xorg-video-ati from the Ubuntu repositories and
> tried to apply the patch to it.

That can't work, as the patch is for the kernel, not the X driver.

You should be able to get the source for your running kernel with

apt-get source linux-image-$(uname -r)

> I've also never tested a kernel mod so I'm not sure what I would do if
> I got the patch to compile.

Boot the patched kernel (or load the patched radeon kernel module) and try to reproduce the problem. Look for the message from comment #6 in dmesg.