[Intel-gfx] [PATCH] drm/i915/glk: Apply WaProgramL3SqcReg1DefaultForPerf for GLK too

[David Weinehall]

On Tue, Nov 14, 2017 at 03:05:03PM +0200, Valtteri Rantala wrote:
> Testing the texture read performance shows that the same tuning for the
> SQ credits is needed on GLK as on BXT/APL. This has been also confirmed
> by Altug from the HW team.
> 
> Cc: Altug Koker <altug.koker at intel.com>
> Signed-off-by: Valtteri Rantala <valtteri.rantala at intel.com>

With comments below, and unless Altug has objections:

Reviewed-by: David Weinehall <david.weinehall at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_engine_cs.c | 17 +++++++++--------
>  1 file changed, 9 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
> index 70bbe8e..11fc0bd 100644
> --- a/drivers/gpu/drm/i915/intel_engine_cs.c
> +++ b/drivers/gpu/drm/i915/intel_engine_cs.c
> @@ -1093,6 +1093,15 @@ static int gen9_init_workarounds(struct intel_engine_cs *engine)
>  	/* WaDisableSTUnitPowerOptimization:skl,bxt,kbl,glk,cfl */
>  	WA_SET_BIT_MASKED(HALF_SLICE_CHICKEN2, GEN8_ST_PO_DISABLE);
>  
> +	/* WaProgramL3SqcReg1DefaultForPerf:bxt,glk */
> +	if (IS_BXT_REVID(dev_priv, BXT_REVID_B0, REVID_FOREVER) ||
> +	    IS_GEMINILAKE(dev_priv)) {

Since we've dropped workarounds for pre-production Broxtons,
I think this could/should be simplified to:

if (IS_BROXTON(dev_priv) || IS_GEMINILAKE(dev_priv)) {

or even

if (IS_GEN9_LP(dev_priv)) {

But that's just nitpicking. The fix is sound from a performance
perspective.

> +		u32 val = I915_READ(GEN8_L3SQCREG1);
> +		val &= ~L3_PRIO_CREDITS_MASK;
> +		val |= L3_GENERAL_PRIO_CREDITS(62) | L3_HIGH_PRIO_CREDITS(2);
> +		I915_WRITE(GEN8_L3SQCREG1, val);
> +	}
> +
>  	/* WaOCLCoherentLineFlush:skl,bxt,kbl,cfl */
>  	I915_WRITE(GEN8_L3SQCREG4, (I915_READ(GEN8_L3SQCREG4) |
>  				    GEN8_LQSC_FLUSH_COHERENT_LINES));
> @@ -1258,14 +1267,6 @@ static int bxt_init_workarounds(struct intel_engine_cs *engine)
>  			return ret;
>  	}
>  
> -	/* WaProgramL3SqcReg1DefaultForPerf:bxt */
> -	if (IS_BXT_REVID(dev_priv, BXT_REVID_B0, REVID_FOREVER)) {
> -		u32 val = I915_READ(GEN8_L3SQCREG1);
> -		val &= ~L3_PRIO_CREDITS_MASK;
> -		val |= L3_GENERAL_PRIO_CREDITS(62) | L3_HIGH_PRIO_CREDITS(2);
> -		I915_WRITE(GEN8_L3SQCREG1, val);
> -	}
> -
>  	/* WaToEnableHwFixForPushConstHWBug:bxt */
>  	if (IS_BXT_REVID(dev_priv, BXT_REVID_C0, REVID_FOREVER))
>  		WA_SET_BIT_MASKED(COMMON_SLICE_CHICKEN2,
> -- 
> 2.7.4