[Mesa-dev] Radeon DRI1 removal

[Alex Deucher]

On Wed, Oct 19, 2011 at 8:50 PM, Eric Anholt <eric at anholt.net> wrote:
> For the MapRenderbuffer() code (See
> http://cgit.freedesktop.org/~anholt/mesa/log/?h=rbmap for the current
> work, which has glReadPixels() converted so far and tested on gen6 with
> only one regression in the tip commit), I need to be able to provide a
> linear mapping of arbitrary renderbuffers.  Radeon's legacy DRI1 support
> gets in the way of that -- I need to use the blitter to a temporary to
> do untiling (which means holding the hw lock across map/unmap cycles,
> and thus refcounting the lock), and I need to do clipping on read and
> write.
>
> I think it would be much better to just ditch DRI1 at this point, since
> KMS and DRI2 are quite well established, and are relied on by shipping
> desktop environments.
>
> Code to do so is at
> http://cgit.freedesktop.org/~anholt/mesa/log/?h=radeon-kill-dri1 which
> is tested on r300 only currently.  No piglit regressions there, though I
> do note that copyteximage is unreliable both before and after (rendering
> always looks good to my eyes, but readback apparently gets junk).
>
> So, Radeon maintainers, what do you think?  And, does anyone else want
> to test it on the other drivers?  I caught two bugs in my r300 testing
> (one too many lines cut in one r300 commit, and I had also removed the
> texsubimage code in an unrelated-to-the-series commit, but it regressed
> s3tc-texsubimage so I backed it out).

I don't see AMD doing any more work on DRI1.  The cleanup would be
nice, but it would also mean dropping support for *BSD.  OTOH, these
drivers aren't likely to see any more changes feature-wise so sticking
with mesa 7.11 would work.  Also, are there are any Linux distros that
care about DRI1 anymore?  If so, speak now.  Also, as Michel said, if
we drop DRI1 support, we might as well drop r300c and r600c altogether
in favor of the gallium variants.

Alex