Re: [PATCH 2/3] drm/i915: Set GPU freq to idle_freq initially

Imre Deak
2016-03-16T17:57:05Z

On Fri, 2016-03-04 at 21:43 +0200, ville.syrjala@linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Currently we set the initial GPU frequency to min_freq_softlimit
> on gen9, and to efficient_freq on VLV/CHV. On all the other platforms
> we set it to idle_freq. Let's use idle_freq across the board to make
> sure we don't waste power. This is especially relevant for VLV since
> Vnn won't drop to minimum unless the GPU is at the minimum frequency.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

Yes, I think having the same logic on all platforms make sense, so:
Reviewed-by: Imre Deak <imre.deak@intel.com>

I noticed that rps.min_freq is always the same as rps.idle_freq, what's
the reason to have both, could we remove one of them? Adding Chris.

> ---
>  drivers/gpu/drm/i915/intel_pm.c | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index c53b8c4d381c..2591d533a895 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -4804,7 +4804,7 @@ static void gen9_enable_rps(struct drm_device *dev)
>    * Up/Down EI & threshold registers, as well as the RP_CONTROL,
>    * RP_INTERRUPT_LIMITS & RPNSWREQ registers */
>   dev_priv->rps.power = HIGH_POWER; /* force a reset */
> - gen6_set_rps(dev_priv->dev, dev_priv->rps.min_freq_softlimit);
> + gen6_set_rps(dev_priv->dev, dev_priv->rps.idle_freq);
>
>   intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
>  }
> @@ -5594,10 +5594,10 @@ static void cherryview_enable_rps(struct drm_device *dev)
>    dev_priv->rps.cur_freq);
>
>   DRM_DEBUG_DRIVER("setting GPU freq to %d MHz (%u)\n",
> -  intel_gpu_freq(dev_priv, dev_priv->rps.efficient_freq),
> -  dev_priv->rps.efficient_freq);
> +  intel_gpu_freq(dev_priv, dev_priv->rps.idle_freq),
> +  dev_priv->rps.idle_freq);
>
> - valleyview_set_rps(dev_priv->dev, dev_priv->rps.efficient_freq);
> + valleyview_set_rps(dev_priv->dev, dev_priv->rps.idle_freq);
>
>   intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
>  }
> @@ -5684,10 +5684,10 @@ static void valleyview_enable_rps(struct drm_device *dev)
>    dev_priv->rps.cur_freq);
>
>   DRM_DEBUG_DRIVER("setting GPU freq to %d MHz (%u)\n",
> -  intel_gpu_freq(dev_priv, dev_priv->rps.efficient_freq),
> -  dev_priv->rps.efficient_freq);
> +  intel_gpu_freq(dev_priv, dev_priv->rps.idle_freq),
> +  dev_priv->rps.idle_freq);
>
> - valleyview_set_rps(dev_priv->dev, dev_priv->rps.efficient_freq);
> + valleyview_set_rps(dev_priv->dev, dev_priv->rps.idle_freq);
>
>   intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
>  }