https://bugs.freedesktop.org/show_bug.cgi?id=91202
--- Comment #27 from Thomas R. freedesktop-bugs@digital-trauma.de --- With amd-staging-4.9, commit a364784ea02674736abd9d345fd74bf6787f95a1 ("drm/amdgpu: expose GPU sensor related information"), it works now, but only if DC is enabled (I guess it's DAL reborn?)
Either I didn't configure DAL correctly before (even though it showed up in dmesg), or there was an actual change that made it work for my card between xmas and now.
Today I lit a candle and deleted fglrx.