Chris, are you using the -k firmware files and associated kernel patches,
updated initrd if needed, etc... ?

My impression is that a few different issues are being discussed in this one
ticket, and that is hampering progress. Not quite sure what the right split
would be (if we were to close this and replace with N more focused tickets) but
probably one of them should be for stability problems when running the -k
firmware and checking whether locking dpm level to performance makes a
difference.