[Intel-gfx] [PATCH] drm/i915/gen9: implement WaEnableSamplerGPGPUPreemptionSupport

[Dave Gordon]

On 19/04/16 15:45, tim.gore at intel.com wrote:
> From: Tim Gore <tim.gore at intel.com>
>
> WaEnableSamplerGPGPUPreemptionSupport fixes a problem
> related to mid thread pre-emption.
>
> Signed-off-by: Tim Gore <tim.gore at intel.com>

Reviewed-by: Dave Gordon <david.s.gordon at intel.com>

> ---
>   drivers/gpu/drm/i915/i915_reg.h         | 1 +
>   drivers/gpu/drm/i915/intel_ringbuffer.c | 7 ++++---
>   2 files changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 9464ba3..2982470b 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -7162,6 +7162,7 @@ enum skl_disp_power_wells {
>
>   #define GEN9_HALF_SLICE_CHICKEN7	_MMIO(0xe194)
>   #define   GEN9_ENABLE_YV12_BUGFIX	(1<<4)
> +#define   GEN9_ENABLE_GPGPU_PREEMPTION	(1<<2)
>
>   /* Audio */
>   #define G4X_AUD_VID_DID			_MMIO(dev_priv->info.display_mmio_offset + 0x62020)
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> index 0d24494..444d30a 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> @@ -959,9 +959,10 @@ static int gen9_init_workarounds(struct intel_engine_cs *engine)
>   	}
>
>   	/* WaEnableYV12BugFixInHalfSliceChicken7:skl,bxt */
> -	if (IS_SKL_REVID(dev, SKL_REVID_C0, REVID_FOREVER) || IS_BROXTON(dev))
> -		WA_SET_BIT_MASKED(GEN9_HALF_SLICE_CHICKEN7,
> -				  GEN9_ENABLE_YV12_BUGFIX);
> +	/* WaEnableSamplerGPGPUPreemptionSupport:skl,bxt */
> +	WA_SET_BIT_MASKED(GEN9_HALF_SLICE_CHICKEN7,
> +			  GEN9_ENABLE_YV12_BUGFIX |
> +			  GEN9_ENABLE_GPGPU_PREEMPTION);
>
>   	/* Wa4x4STCOptimizationDisable:skl,bxt */
>   	/* WaDisablePartialResolveInVc:skl,bxt */
>