Removing direct graphics access from DGA

Keith Packard keithp at
Sun Sep 20 14:00:50 PDT 2009

Excerpts from Simon Thum's message of Sun Sep 20 12:52:09 -0700 2009:

> FWIW, the GGI ( has had a backend for X/DGA, and it was
> even faster than non-DGA on XFree 3.6 or so. So something worked
> sometime.

Yes, I've seen DGA work, and it could be made to work again on at
least some of our hardware. However, it's been broken for any driver
exposing RandR 1.2, and the last bug report about this was from
2007. Either people have given up hoping to see this fixed or they
just aren't using it anymore.

In any case, the mmap API can't be exposed reliably for resizeable
frame buffers as there's no way to revoke a mapping.
keith.packard at

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