https://bugs.freedesktop.org/show_bug.cgi?id=84500
--- Comment #28 from Christian König deathsimple@vodafone.de --- (In reply to Alexandre Demers from comment #27)
(In reply to Christian König from comment #22)
Keep in mind that this might actually be a user space problem and that different kernel versions work or don't work only be coincident.
If you can get me an SSH access to the box I could take a look as well. Attaching a debugger to the process in question shouldn't be to hard.
By the way, if I understand correctly, if the bug is in userspace and was introduced around the same time kernel 3.17-rcX went out, would it appears when using a previous kernel version? I'm trying to figure out a way to distinguish one from the other because from where I am in the bisection, I was unable to reproduce the bug with a 3.16 kernel, but it does appear before 3.17-rc1...
It is possible that a new kernel let this problem surface by coincident. E.g. a slightly different memory layout or allocation timing and instead of changing two random pixel on the screen we change the command buffer and the whole box crashes and/or shows this error.
All you can do is to try to figure out when the corruption happens. The kernel copies the command buffer content from userspace to a kernel buffer and then checks the content of the kernel buffer. Might be a good idea to print the content of the userspace buffer as well and compare both?