[Nouveau] nv50: wfb patches

[Younes Manton]

2009/3/29 Maarten Maathuis <madman2003 at gmail.com>:
> The whole thing works fine, but XSHM is an issue
> (http://stillunknown.livejournal.com/928.html). With it disabled most
> apps are fine, although a few issues remain.

Just out of curiousity, why can't you alloc a pixmap you can
accelerate and just keep it sync'd with the xshm pixmap, track dirty
rects, etc? Also why can't you allocate a linear pixmap on software
fallbacks, copy+untile the original to the linear, let the fallback
complete, and copy+tile back to the original? Might be cheaper than
having to trap and transform every pixel access.