https://bugs.freedesktop.org/show_bug.cgi?id=46796
--- Comment #8 from Michel Dänzer michel@daenzer.net 2012-03-07 00:21:12 PST --- (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.
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