EXA - when does it's implementation depend on DRM?

[Rafał Miłecki]

AFAIU EXA is collection of operations (Solid, Copy, UploadToScreen,
DownloadFromScreen) that touch VRAM. So we can tell hardware to move
xterm window 100px right (Copy) and fill freed place with blue
(Solid). Is that right?

So my question is: when implementing EXA (in DDX) needs DRM and when
it does not? I know in case of R6xx-R7xx we had to get DRM first to
receive EXA. AFAIK it wasn't the case with R1xx-R5xx.

On the other hand some VIA's driver needs DRM for EXA on Chrome9,
while openChrome claims to support EXA without DRM[1].

Could someone explain this to me, please?

[1] http://phoronix.com/forums/showthread.php?p=89776

-- 
Rafał