[Mesa-dev] [PATCH] intel/blorp: Define the clear value bounds for HiZ clears

[Nanley Chery]

On Mon, Oct 29, 2018 at 12:48:50PM +0100, Juan A. Suarez Romero wrote:
> On Thu, 2018-10-25 at 16:25 -0700, nanleychery at gmail.com wrote:
> > From: Nanley Chery <nanley.g.chery at intel.com>
> > 
> > Follow the restriction of making sure the clear value is between the min
> > and max values defined in CC_VIEWPORT. Avoids a simulator warning for
> > some piglit tests, one of them being:
> > 
> > ./bin/depthstencil-render-miplevels 146 d=z32f_s8
> > 
> > Jason found this to make a GPU hang go away on SKL.
> > 
> > Fixes: 09948151ab1d5184b4dd9052bb1f710fa1e00a7b
> >        ("intel/blorp: Add the BDW+ optimized HZ_OP sequence to BLORP")
> 
> 
> As 09948151ab1 ("intel/blorp: Add the BDW+ optimized HZ_OP sequence to BLORP")
> is included in 18.2 branch, adding this to 18.2 queue.
> 
> It doesn't apply cleanly, so I've fixed the conflicts. You can check the fixed
> commit at:
> 
> 
> https://gitlab.freedesktop.org/mesa/mesa/commit/aaff8c7a0ed55d71e9dd0a6fef6905d6a2536c3f
> 

Looks good to me. The placement of this instruction in the batch is
different in the stable branch (after 3DSTATE_WM) vs the master branch
(before 3DSTATE_WM). This will cause some noise when diff'ing dumps of
the batches, but it's not a big deal.

-Nanley

> 	J.A.
> 
> > ---
> >  src/intel/blorp/blorp_genX_exec.h | 14 ++++++++++++++
> >  1 file changed, 14 insertions(+)
> > 
> > diff --git a/src/intel/blorp/blorp_genX_exec.h b/src/intel/blorp/blorp_genX_exec.h
> > index 50341ab0ecf..7a8c45dbee5 100644
> > --- a/src/intel/blorp/blorp_genX_exec.h
> > +++ b/src/intel/blorp/blorp_genX_exec.h
> > @@ -1628,6 +1628,20 @@ blorp_emit_gen8_hiz_op(struct blorp_batch *batch,
> >      */
> >     blorp_emit_3dstate_multisample(batch, params);
> >  
> > +   /* From the BDW PRM Volume 7, Depth Buffer Clear:
> > +    *
> > +    *    The clear value must be between the min and max depth values
> > +    *    (inclusive) defined in the CC_VIEWPORT. If the depth buffer format is
> > +    *    D32_FLOAT, then +/-DENORM values are also allowed.
> > +    *
> > +    * Set the bounds to match our hardware limits, [0.0, 1.0].
> > +    */
> > +   if (params->depth.enabled && params->hiz_op == ISL_AUX_OP_FAST_CLEAR) {
> > +      assert(params->depth.clear_color.f32[0] >= 0.0f);
> > +      assert(params->depth.clear_color.f32[0] <= 1.0f);
> > +      blorp_emit_cc_viewport(batch);
> > +   }
> > +
> >     /* If we can't alter the depth stencil config and multiple layers are
> >      * involved, the HiZ op will fail. This is because the op requires that a
> >      * new config is emitted for each additional layer.
>