Comment # 19 on bug 73191 from Alex Deucher

(In reply to comment #18)
> I was replying to vladi, who reported it on a 7540D

That's also a different family (northern islands) which is handled by the the
r600 driver rather than radeonsi.

r600 driver:
r6xx, r7xx, evergreen, northern islands families

radeonsi driver:
southern islands, sea islands families


That said, the commit in question hits both drivers.