[Intel-gfx] [PATCH] tools/null_state/gen9: Send atleast one valid component in VF state

[Ben Widawsky]

On Fri, Jul 31, 2015 at 04:27:07PM +0100, Arun Siluvery wrote:
> A programming restriction exists for this instruction, atleast one component
> of one valid vertex element must be enabled.
> 
> Cc: Ben Widawsky <benjamin.widawsky at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Signed-off-by: Arun Siluvery <arun.siluvery at linux.intel.com>
> ---
>  tools/null_state_gen/intel_renderstate_gen9.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/null_state_gen/intel_renderstate_gen9.c b/tools/null_state_gen/intel_renderstate_gen9.c
> index 6f808f8..b3766ea 100644
> --- a/tools/null_state_gen/intel_renderstate_gen9.c
> +++ b/tools/null_state_gen/intel_renderstate_gen9.c
> @@ -440,7 +440,12 @@ int gen9_setup_null_render_state(struct intel_batchbuffer *batch)
>  	/* Vertex buffers */
>  	gen8_emit_vertex_buffers(batch);
>  	gen8_emit_vertex_elements(batch);
> -	OUT_CMD(GEN9_3DSTATE_COMPONENT_PACKING, 5);
> +
> +	OUT_BATCH(GEN9_3DSTATE_COMPONENT_PACKING | 3);
> +	OUT_BATCH(1);
> +	OUT_BATCH(0);
> +	OUT_BATCH(0);
> +	OUT_BATCH(0);
>  
>  	OUT_BATCH(GEN6_3DSTATE_VF_STATISTICS | 1 /* Enable */);
>  

Like I said on IRC, I don't think this does anything unless you set bit 9 of
3DSTATE_VF.0. Also, I believe you should be setting 0xf, not 1 since you'd want
to use all 4 components.

So I'm not really sure what we're aiming to do. If you make it 0xf, and add a
comment about how this command doesn't do anything because we're not setting up
3DSTATE_VF packing, it's:
Reviewed-by: Ben Widawsky <ben at bwidawsk.net>

I'm still more in favor of dropping the command altogether, that too would be:
Reviewed-by: Ben Widawsky <ben at bwidawsk.net>

-- 
Ben Widawsky, Intel Open Source Technology Center