(In reply to charlie from comment #13)
> I'm now using "drm-next-4.8-wip" (from
> https://cgit.freedesktop.org/~agd5f/linux/).  I still require
> "fiji_disable_pcie_dpm.diff" to overcome the bug.  I can't remember if
> "disable_gen3.diff" no longer patches cleanly or does not work once the
> kernel is compiled.  In any case, "disable_gen3.diff" is no longer effective.
> 
> Is this a bios issue?  If so, then I can upgrade to the latest bios for my
> motherboard to see if the bug persists without patching the kernel.

It could be.  Does a new bios help?  We've seen similar issues with certain
boards internally.  What CPU/motherboard is this?  If your board has options
for configuring the default pcie gen or generic pcie performance options does
changing any of them help?