[Intel-gfx] [PATCH 09/10] drm/i915: gen 9 h/w w/a (WaForceEnableNonCoherent)

[Damien Lespiau]

On Thu, Feb 05, 2015 at 10:47:24AM +0000, Nick Hoath wrote:
> From: "Hoath, Nicholas" <nicholas.hoath at intel.com>
> 
> Add:
> WaForceEnableNonCoherent
> 
> v1: Don't add WaHdcDisableFetchWhenMasked. Add stepping check for WaForceEnableNonCoherent
> 
> Signed-off-by: Nick Hoath <nicholas.hoath at intel.com>

Reviewed-by: Damien Lespiau <damien.lespiau at intel.com>

-- 
Damien

> ---
>  drivers/gpu/drm/i915/intel_ringbuffer.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> index 066b63d..36885b4 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> @@ -902,6 +902,17 @@ static int gen9_init_workarounds(struct intel_engine_cs *ring)
>  				  GEN9_ENABLE_YV12_BUGFIX);
>  	}
>  
> +	if (INTEL_REVID(dev) <= SKL_D0_REVID) {
> +		/*
> +		 *Use Force Non-Coherent whenever executing a 3D context. This
> +		 * is a workaround for a possible hang in the unlikely event
> +		 * a TLB invalidation occurs during a PSD flush.
> +		 */
> +		/* WaForceEnableNonCoherent:skl */
> +		WA_SET_BIT_MASKED(HDC_CHICKEN0,
> +				  HDC_FORCE_NON_COHERENT);
> +	}
> +
>  	/* Wa4x4STCOptimizationDisable:skl */
>  	WA_SET_BIT_MASKED(CACHE_MODE_1, GEN8_4x4_STC_OPTIMIZATION_DISABLE);
>  
> -- 
> 2.1.1
>