I have a Kaveri 7400K on ASRock FM2A58M-VG3+. Running Fedora 25, KMS works and
it boots nicely, but instead of GDM running on Wayland, I get screen full of
colored noise. Using Xorg makes no difference.

Phoronix claims this APU worked in 2014[1]. It never worked for me with the
open source driver (previously not even KMS worked), however it worked
perfectly with fglrx last time I tried it.

I can try older Mesa and LLVM if that would be useful, but compiling it will
take a while.

[1] https://www.phoronix.com/scan.php?page=article&item=amd_apus_august&num=1