[Intel-gfx] [PATCH igt] tools/null_state_gen: Don't upload color calc and depth stencil on gen6

[Chris Wilson]

Quoting Mika Kuoppala (2017-08-08 14:36:59)
> Mika Kuoppala <mika.kuoppala at linux.intel.com> writes:
> 
> > We were pointing the color calc and depth stencil states blindly
> > to an offset of 1k from bb start. This was foolhardy as it collides
> > with other state in the batch and results in a wrecked state upload.
> >
> > Chris noticed that with snb gt1, it takes 10 seconds for renderstate batch
> > to complete. However pointing the states to a known valid 64 aligned
> > zero blocks didn't work to reduce the upload time either.
> >
> > Cave in and omit uploading color calc and depth stencil states.
> 
> Not just yet, ignore this patch.

Right, we found the root cause for my issue, so we can actually load the
correct state here (i.e. create a NUL block and point both depth-stencil
and color-calc to it). We could use that same block for the blend state
as well, etc.
-Chris