Re: [PATCH] drm/i915/bdw: Disable centroid pixel perf optimization

[Jesse Barnes <jbarnes@virtuousgeek.org>]

On Mon,  4 Nov 2013 22:52:39 -0800
Ben Widawsky <benjamin.widawsky@intel.com> wrote:

> From: Ben Widawsky <ben@bwidawsk.net>
> 
> BDW-A workaround
> 
> BDW Bug #1899532
> 
> v2: WARN on when not using preliminary HW support
> 
> Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
> ---
>  drivers/gpu/drm/i915/i915_reg.h | 3 +++
>  drivers/gpu/drm/i915/intel_pm.c | 4 ++++
>  2 files changed, 7 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 050f8c1..98961ef 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -4989,6 +4989,9 @@
>  #define HSW_ROW_CHICKEN3		0xe49c
>  #define  HSW_ROW_CHICKEN3_L3_GLOBAL_ATOMICS_DISABLE    (1 << 6)
>  
> +#define HALF_SLICE_CHICKEN3		0xe184
> +#define   GEN8_CENTROID_PIXEL_OPT_DIS	(1<<8)
> +
>  #define G4X_AUD_VID_DID			(dev_priv->info->display_mmio_offset + 0x62020)
>  #define INTEL_AUDIO_DEVCL		0x808629FB
>  #define INTEL_AUDIO_DEVBLC		0x80862801
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index e6e12e1..66b5a1c 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -5286,6 +5286,10 @@ static void gen8_init_clock_gating(struct drm_device *dev)
>  	I915_WRITE(WM2_LP_ILK, 0);
>  	I915_WRITE(WM1_LP_ILK, 0);
>  
> +	WARN(!i915_preliminary_hw_support,
> +	     "GEN8_CENTROID_PIXEL_OPT_DIS not be needed for production\n");
> +	I915_WRITE(HALF_SLICE_CHICKEN3,
> +		   _MASKED_BIT_ENABLE(GEN8_CENTROID_PIXEL_OPT_DIS));
>  	I915_WRITE(GAMTARBMODE, _MASKED_BIT_ENABLE(ARB_MODE_BWGTLB_DISABLE));
>  
>  	/* WaSwitchSolVfFArbitrationPriority */

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>

-- 
Jesse Barnes, Intel Open Source Technology Center