[Mesa-dev] [PATCH 2/7] i965: Turn the INTEL_FORCE_GS env var into a driconf option.

[Kenneth Graunke]

On 03/06/2012 02:57 PM, Eric Anholt wrote:
> ---
>   src/mesa/drivers/dri/i965/brw_context.c   |    1 +
>   src/mesa/drivers/dri/i965/brw_context.h   |    3 +++
>   src/mesa/drivers/dri/i965/brw_gs.c        |    3 +--
>   src/mesa/drivers/dri/intel/intel_screen.c |    6 +++++-
>   4 files changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/src/mesa/drivers/dri/i965/brw_context.c b/src/mesa/drivers/dri/i965/brw_context.c
> index 65de260..30db5b4 100644
> --- a/src/mesa/drivers/dri/i965/brw_context.c
> +++ b/src/mesa/drivers/dri/i965/brw_context.c
> @@ -313,6 +313,7 @@ brwCreateContext(int api,
>      brw_draw_init( brw );
>
>      brw->precompile = driQueryOptionb(&intel->optionCache, "shader_precompile");
> +   brw->gs.force_enable = driQueryOptionb(&intel->optionCache, "force_gs");
>
>      ctx->Const.NativeIntegers = true;
>      ctx->Const.UniformBooleanTrue = 1;
> diff --git a/src/mesa/drivers/dri/i965/brw_context.h b/src/mesa/drivers/dri/i965/brw_context.h
> index a16145b..507720d 100644
> --- a/src/mesa/drivers/dri/i965/brw_context.h
> +++ b/src/mesa/drivers/dri/i965/brw_context.h
> @@ -865,6 +865,9 @@ struct brw_context
>         struct brw_gs_prog_data *prog_data;
>
>         bool prog_active;
> +      /** Debug option to always enable a passthrough GS program */
> +      bool force_enable;
> +
>         /** Offset in the program cache to the CLIP program pre-gen6 */
>         uint32_t prog_offset;
>         uint32_t state_offset;
> diff --git a/src/mesa/drivers/dri/i965/brw_gs.c b/src/mesa/drivers/dri/i965/brw_gs.c
> index bfca169..cbcd31f 100644
> --- a/src/mesa/drivers/dri/i965/brw_gs.c
> +++ b/src/mesa/drivers/dri/i965/brw_gs.c
> @@ -234,8 +234,7 @@ static void populate_key( struct brw_context *brw,
>      /* For testing, the environment variable INTEL_FORCE_GS can be used to
>       * force a GS program to be used, even if it's not necessary.
>       */
> -   if (getenv("INTEL_FORCE_GS"))
> -      key->need_gs_prog = true;
> +   key->need_gs_prog = brw->gs.force_enable;
>   }
>
>   /* Calculate interpolants for triangle and line rasterization.
> diff --git a/src/mesa/drivers/dri/intel/intel_screen.c b/src/mesa/drivers/dri/intel/intel_screen.c
> index 48762d0..39c9fb4 100644
> --- a/src/mesa/drivers/dri/intel/intel_screen.c
> +++ b/src/mesa/drivers/dri/intel/intel_screen.c
> @@ -83,10 +83,14 @@ PUBLIC const char __driConfigOptions[] =
>         DRI_CONF_OPT_BEGIN(shader_precompile, bool, false)
>   	 DRI_CONF_DESC(en, "Perform code generation at shader link time.")
>         DRI_CONF_OPT_END
> +
> +      DRI_CONF_OPT_BEGIN(force_gs, bool, false)
> +	 DRI_CONF_DESC(en, "Always use a passthrough GS program on gen4/5.")
> +      DRI_CONF_OPT_END

IMHO this patch is not useful.  Paul actually added this to force the HW 
to always use a passthrough GS program on Gen *6* during his transform 
feedback work.

I have no idea if forcing the GS to be enabled -ever- worked on gen4/5. 
  It also doesn't appear to be used on Gen6.

So, I'd just delete the env. var and not bother making it a driconf option.

>      DRI_CONF_SECTION_END
>   DRI_CONF_END;
>
> -const GLuint __driNConfigOptions = 13;
> +const GLuint __driNConfigOptions = 14;
>
>   #include "intel_batchbuffer.h"
>   #include "intel_buffers.h"