https://bugs.freedesktop.org/show_bug.cgi?id=102500
--- Comment #19 from charlie bug0xa3d2@hushmail.com --- Bug 102500 might be related to bug 102598.
I tried to apply patch attachment 134082 to amd-staging-4.12 (~agd5f/linux) kernel and drm-next-4.15-wip but it does not apply cleanly. I applied it manually to drm-next-4.15-wip and that kernel would not finish compiling.