[Mesa-dev] Radeon DRI1 removal

[Roland Scheidegger]

Am 20.10.2011 18:10, schrieb Dave Airlie:
>>>
>>> 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.
> 
> Hell yes, drop r300c and r600c as well.
> 
> We can get DRI2 tiling working on r100/r200 again then with texture
> mapping as previously they relied on us knowing the tiling formats
> which are totally undocumented and I never figured out in sw.

Ahh brings back fond memories of hacking around to make texture
macro/micro tiling work for all (mip) sizes (and figuring out when it
won't if texture had "bad" width/height proportions). I think I actually
figured out the tiling pattern for both r100 and r200 at some point, it
was not that complicated. In any case the micro tiling pattern can still
be seen in the kernel code since hacks were necessary to make it work
with blitter if the texture width was too small (though I always thought
this to be quite fishy, maybe it would have been possible to make it
work with less hacks by programming the blitter more appropriately). A
lot of trial and error was needed though for that but the performance
gain is definitely worth it (as is hyperz - IIRC you get about half the
performance if you have neither hyperz nor color tiling for typical
fillrate-bound situations on r2xx).

Roland