https://bugzilla.kernel.org/show_bug.cgi?id=196337
--- Comment #4 from Johannes Hirte (johannes.hirte@datenkhaos.de) --- I've added pg_mask=0xFFFFFFFE as suggested by Tom St Denis at https://lists.freedesktop.org/archives/amd-gfx/2017-August/012329.html
This works for me, so I don't need to modify the code anymore. But this really should be fixed upstream. So please tell me, you need more infos or if you have something for testing.