Comment 29 for bug 1216252

If you are keen, you can try:

the userptr branch from http://cgit.freedesktop.org/~ickle/linux-2.6

and compiling the ddx with ./configure --enable-userptr <usual configure options>

The difference will be subtle, only a path where we need to operate on a busy target will use the userptr directly. At the moment, we will allocate a staging buffer to perform the copy. My feeling is that we are missing some barrier around that staging buffer and the GPU reads garbage instead of the updated content from chromium. So if switching to userptr does fix the corruption, I think that points towards the staging buffer.