[Mesa-dev] [v2] Compression support for single-sampled

[Pohjolainen, Topi]

On Thu, Feb 11, 2016 at 04:03:00PM -0800, Ben Widawsky wrote:
> On Thu, Feb 11, 2016 at 08:33:53PM +0200, Topi Pohjolainen wrote:
> > This series enables compression for single sampled color surfaces,
> > also referred to as "lossless compression". This is yet only for
> > driver internal use easing pressure on memory bandwidth and caches
> > when writing, blending and sampling surfaces uing gpu.
> > 
> > As a side effect the need for color buffer resolves after fast
> > clears is also decreased. Current understanding is that sampling
> > engine doesn't understand meta data (auxiliary buffer) for single
> > sampled fast cleared surfaces. However, if the meta data is written
> > with lossless compression enabled, even sampling engine is capable
> > of reading both the color buffer and the auxiliary, and resolves
> > can be omitted in those case.
> > 
> > The final enabling patch is dependent on earlier two-patch series
> > fixing state restore mechanism in i965-meta operations.
> > 
> > v2 (Ben):  Use combination of msaa_layout and number of samples
> >            instead of introducing explicit type for lossless
> >            compression.
> > 
> 
> Other than the comments I left,
> patch 6, 7, 9, 10 are:
> Reviewed-by: Ben Widawsky <benjamin.widawsky at intel.com>
> 
> I wouldn't mind a small comment in patch 6 about why INTEL_MSAA_LAYOUT_NONE is
> fast clear (it seems like the resolve has such a comment)... up to you. A few 
> months from now I can imagine myself looking at it and being WTF.
> 
> 6 and 9 would be a logical pair to squash IMO.

I agree, I squashed them and added a comment:

/* Only single sampled surfaces need to (and actually can) be resolved. */

> 
> I'm going to start back up tomorrow at patch #11. I want to take a bit of a
> break.

Thanks!