https://bugs.freedesktop.org/show_bug.cgi?id=107154
--- Comment #2 from freedesktop.org@nentwig.biz --- (In reply to dwagner from comment #1)
I currently work around S3 resume crashes by switching to the console display before enterin S3 sleep - but this is really an awkward work-around.
Oh, that doesn't help either. It crashes the very moment I switch back to X.
And what's more starting with 4.15 amdgpu.dc=0 doesn't appear to make any difference.