xf86-video-intel 2.5 release planning

[Jesse Barnes]

It's my turn to handle a 2D driver release again, so I've been thinking about 
what we should include (and remove!) in the 2.5 release.  I've created a 
blocker bug for the release, 16926, and I'm interested in hearing about bugs 
you think should be added.  The 2.4 release was a bit late; I'd like to avoid 
that this time around, and want to do the first -rc hopefully by mid-August.

Target highlights for this release include:
  1) usable EXA support
  2) support for GEM (if supported by the currently running kernel)
  3) support for kernel mode setting (again, if the underlying kernel supports
     it)
  4) no more video tearing with textured video & XvMC
  5) Bug fixing
  6) removal of XAA code
See below for details.

1. Usable EXA support
Carl recently pushed some fixes that should make EXA better than XAA 
(finally): http://cworth.org/blog/technical/.  Assuming the users reporting 
performance regressions with EXA vs. XAA are happy with the changes, things 
are looking good here.

2. Support for GEM
The drm-gem branch of xf86-video-intel has been under development for awhile 
now, and gracefully falls back in the case where no kernel support is 
available.  I'd like to merge this into master to get it some more coverage.  
Ideally, we'd get the Mesa drm-gem branch merged into master as well, making 
it much easier for people to play with GEM stuff (just boot a new kernel or 
insmod some new DRM modules and restart), but the Mesa bits need a little 
more review first.

3. Support for kernel mode setting
Along the same lines, we'd like to make it easy for people to test the shiny, 
new kernel mode setting bits.  The 2D driver changes aren't hugely invasive 
(and they give me an excuse to clean some stuff up), so I'm planning on 
merging them to master, again to make testing of new kernel bits easier for 
everyone.

4. No more video tearing
One of our #1 complaints since adding textured video support is tearing.  It 
seems to occur in both composited and non-composited configurations, 
depending on what else is going on in the system.  With recent changes to 
Mesa, hopefully the composited case can be solved by making the compositing 
manager use scheduled buffer swaps (i.e. using glxSwapBuffers with 
vblank_mode=3 or similar), but in the non-composited case we'll need to make 
our Xv and XvMC code a bit smarter.

5. Bug fixing
Catch all for fixing display bugs, suspend resume problems, improving LFP 
detection, fixing SDVO bugs, etc. (there are quite a few display bugs Zhenyu 
& I want to tackle for this release)

6. No more XAA
Back in 2.2, we made EXA the default acceleration architecture for the driver.  
It obviously wasn't quite ready back then for everything people were throwing 
at it, but OTOH it didn't have some of the fundamental shortcomings of XAA.  
It looks like it's finally ready though, so assuming Carl has EXA performance 
well in-hand, we should be able to delete the XAA code altogether (which will 
be nice since it doesn't support several features and has bugs we don't want 
to fix).

Please direct comments & questions to myself and the list.

Thanks
Jesse