Re: [PATCH 54/89] drm/i915/skl: Enable Gen9 RC6

[Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>]

Damien Lespiau <damien.lespiau@xxxxxxxxx> writes:

> From: Zhe Wang <zhe1.wang@xxxxxxxxx>
>
> Configure and enable RC6 for Gen9.
>
> v2: Rebase on top of BDW rc6 support (Damien)
>
> Signed-off-by: Zhe Wang <zhe1.wang@xxxxxxxxx>
> Signed-off-by: Damien Lespiau <damien.lespiau@xxxxxxxxx>
> ---
>  drivers/gpu/drm/i915/intel_pm.c | 52 ++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 51 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index fdf297f..74a8519 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -4332,6 +4332,13 @@ static void gen8_disable_rps_interrupts(struct drm_device *dev)
>  	}
>  }
>  
> +static void gen9_disable_rps(struct drm_device *dev)
> +{
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +
> +	I915_WRITE(GEN6_RC_CONTROL, 0);
> +}
> +
>  static void gen6_disable_rps_interrupts(struct drm_device *dev)
>  {
>  	struct drm_i915_private *dev_priv = dev->dev_private;
> @@ -4579,6 +4586,45 @@ void bdw_software_turbo(struct drm_device *dev)
>  			&current_time, &current_c0);
>  }
>  
> +static void gen9_enable_rps(struct drm_device *dev)
> +{
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +	struct intel_engine_cs *ring;
> +	uint32_t rc6_mask = 0;
> +	int unused;
> +
> +	/* 1a: Software RC state - RC0 */
> +	I915_WRITE(GEN6_RC_STATE, 0);
> +
> +	/* 1b: Get forcewake during program sequence. Although the driver
> +	 * hasn't enabled a state yet where we need forcewake, BIOS may have.*/
> +	gen6_gt_force_wake_get(dev_priv, FORCEWAKE_ALL);
> +
> +	/* 2a: Disable RC states. */
> +	I915_WRITE(GEN6_RC_CONTROL, 0);
> +
> +	/* 2b: Program RC6 thresholds.*/
> +	I915_WRITE(GEN6_RC6_WAKE_RATE_LIMIT, 54 << 16);

40 << 16

> +	I915_WRITE(GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
> +	I915_WRITE(GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
> +	for_each_ring(ring, dev_priv, unused)
> +		I915_WRITE(RING_MAX_IDLE(ring->mmio_base), 10);
> +	I915_WRITE(GEN6_RC_SLEEP, 0);
> +	I915_WRITE(GEN6_RC6_THRESHOLD, 37500); /* 37.5/125ms per EI */

50000 50ms/125ms per EI

> +
> +	/* 3a: Enable RC6 */
> +	if (intel_enable_rc6(dev) & INTEL_RC6_ENABLE)
> +		rc6_mask = GEN6_RC_CTL_RC6_ENABLE;
> +	DRM_INFO("RC6 %s\n", (rc6_mask & GEN6_RC_CTL_RC6_ENABLE) ?
> +			"on" : "off");
> +	I915_WRITE(GEN6_RC_CONTROL, GEN6_RC_CTL_HW_ENABLE |
> +				   GEN6_RC_CTL_EI_MODE(1) |
> +				   rc6_mask);
> +
> +	gen6_gt_force_wake_put(dev_priv, FORCEWAKE_ALL);
> +
> +}
> +
>  static void gen8_enable_rps(struct drm_device *dev)
>  {
>  	struct drm_i915_private *dev_priv = dev->dev_private;
> @@ -6158,7 +6204,9 @@ void intel_disable_gt_powersave(struct drm_device *dev)
>  		intel_suspend_gt_powersave(dev);
>  
>  		mutex_lock(&dev_priv->rps.hw_lock);
> -		if (IS_CHERRYVIEW(dev))
> +		if (INTEL_INFO(dev)->gen >= 9)
> +			gen9_disable_rps(dev);
> +		else if (IS_CHERRYVIEW(dev))
>  			cherryview_disable_rps(dev);
>  		else if (IS_VALLEYVIEW(dev))
>  			valleyview_disable_rps(dev);
> @@ -6184,6 +6232,8 @@ static void intel_gen6_powersave_work(struct work_struct *work)
>  		cherryview_enable_rps(dev);
>  	} else if (IS_VALLEYVIEW(dev)) {
>  		valleyview_enable_rps(dev);
> +	} else if (INTEL_INFO(dev)->gen >= 9) {
> +		gen9_enable_rps(dev);
>  	} else if (IS_BROADWELL(dev)) {
>  		gen8_enable_rps(dev);
>  		__gen6_update_ring_freq(dev);
> -- 
> 1.8.3.1

I couldn't find out if those values suggested are newer than the values
in this patch. We need to visit this are when we are wiser.

Reviewed-by: Mika Kuoppala <mika.kuoppala@xxxxxxxxx>

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