Re: [PATCH] i965: Fix the VS thread limits for GT1, and clarify the WM limits on both.

[Kenneth Graunke <kenneth@whitecape.org>]

On 03/29/2011 03:17 PM, Eric Anholt wrote:
> ---
>
> I don't have GT1 to test with.  Does this fix VS regressions for
> people with that hardware?

Me neither, but it sure looks correct.

[snip]
> diff --git a/src/mesa/drivers/dri/i965/brw_context.c b/src/mesa/drivers/dri/i965/brw_context.c
> index 9483ec6..a74ba5c 100644
> --- a/src/mesa/drivers/dri/i965/brw_context.c
> +++ b/src/mesa/drivers/dri/i965/brw_context.c
> @@ -183,8 +183,17 @@ GLboolean brwCreateContext( int api,
>      /* WM maximum threads is number of EUs times number of threads per EU. */
>      if (intel->gen>= 6) {
>         brw->urb.size = 1024;
> -      brw->vs_max_threads = 60;
> -      brw->wm_max_threads = 80;
> +      if (IS_GT2(intel->intelScreen->deviceID)) {
> +	 /* This could possibly be 80, but is supposed to require
> +	  * disabling of WIZ hashing (bit 6 of GT_MODE, 0x20d0) and a
> +	  * GPU reset to change.
> +	  */
> +	 brw->wm_max_threads = 40;
> +	 brw->vs_max_threads = 60;
> +      } else {
> +	 brw->wm_max_threads = 40;
> +	 brw->vs_max_threads = 24;
> +      }

Presumably 60 = 12 EUs * 5 threads/EU (for GT2), while 24 = 6 EUs * 4 
threads/EU (for GT1).  If so, a comment to that effect would be nice...

I still have no idea where 40/80 come from.

[snip]
> diff --git a/src/mesa/drivers/dri/intel/intel_chipset.h b/src/mesa/drivers/dri/intel/intel_chipset.h
> index 4ff9140..f7dcf47 100644
> --- a/src/mesa/drivers/dri/intel/intel_chipset.h
> +++ b/src/mesa/drivers/dri/intel/intel_chipset.h

Drop the intel_chipset.h changes, I just committed an equivalent patch.