[Nouveau] Question on Render Targets Register: Array Mode

[Ilia Mirkin]

On Sat, Oct 13, 2018 at 5:40 PM Fernando Sahmkow <fsahmkow27 at gmail.com> wrote:
>
> So there's a register in Render Targets called Array Mode:
> https://github.com/envytools/envytools/blob/master/rnndb/graph/gf100_3d.xml#L289
>
> We've witnessed values of 1 and 6 (array mode -> layers) but we can't tell their meaning. Do you guys got any related info?

https://cgit.freedesktop.org/mesa/mesa/tree/src/gallium/drivers/nouveau/nvc0/nvc0_state_validate.c#n224

It's just the number of layers in the RT. We never appear to set the
VOLUME bit -- I'd assume it's needed for 3d tiling to work properly,
but seemingly not.

(The number of layers is important for shaders that might set gl_Layer
-- the number of layers allowed is controlled by this setting -- it
might not be the full number of layers in the underlying resource due
to e.g. texture views.)

Cheers,

  -ilia