https://bugzilla.kernel.org/show_bug.cgi?id=73291
--- Comment #7 from Alex Deucher alexdeucher@gmail.com --- (In reply to Mike Cloaked from comment #6)
Perhaps this warning will not occur when kernel 3.14.x is used when it is released to arch in the near future. I presume that new patches in kernel 3.13.7 makes the difference between a successful boot to graphical screen in 3.13.6 and fail in 3.13.7 but it would be nice to know if there is a workaround until this is resolved in kernel > 3.13.7?
Can you bisect? If the warning is related to the problem, it's an intel driver issue rather than a radeon driver issue. Does the system work ok if you blacklist the radeon driver? E.g., add modprobe.blacklist=radeon to the kernel command line in grub.