Re: [PATCH 7/8] drm/i915: Use cdclk_state->voltage on CNL

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Wed, Oct 18, 2017 at 08:48:24PM +0000, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> Track the system agent voltage we request from pcode in the cdclk state
> on CNL. Annoyingly we can't actually read out the current value since
> there's no pcode command to do that, so we'll have to just assume that
> it worked.

+static u32 cnl_cur_voltage(struct drm_i915_private *dev_priv)
+{
+       u32 voltage;
+       sandybridge_pcode_read(dev_priv, SKL_PCODE_CDCLK_CONTROL, &voltage);
+       return voltage;
+}
+
 static void cnl_get_cdclk(struct drm_i915_private *dev_priv,
                         struct intel_cdclk_state *cdclk_state)
 {
@@ -1486,8 +1493,7 @@ static void cnl_get_cdclk(struct drm_i915_private *dev_priv,
 
        cdclk_state->cdclk = DIV_ROUND_CLOSEST(cdclk_state->vco, div);
 
+       cdclk_state->voltage = cnl_cur_voltage(dev_priv);
 }
 
 static void cnl_cdclk_pll_disable(struct drm_i915_private *dev_priv)
@@ -1594,8 +1600,7 @@ static void cnl_set_cdclk(struct drm_i915_private *dev_priv,
 
        intel_update_cdclk(dev_priv);
 
+       dev_priv->cdclk.hw.voltage = cnl_cur_voltage(dev_priv);


> 
> Cc: Mika Kahola <mika.kahola@intel.com>
> Cc: Manasi Navare <manasi.d.navare@intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_cdclk.c | 44 ++++++++++++++++++++++++--------------
>  1 file changed, 28 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_cdclk.c b/drivers/gpu/drm/i915/intel_cdclk.c
> index 1b4dcd9689da..795a18f64c4c 100644
> --- a/drivers/gpu/drm/i915/intel_cdclk.c
> +++ b/drivers/gpu/drm/i915/intel_cdclk.c
> @@ -1505,6 +1505,19 @@ static int cnl_calc_cdclk(int min_cdclk)
>  		return 168000;
>  }
>  
> +static u8 cnl_calc_voltage(int cdclk)
> +{
> +	switch (cdclk) {
> +	default:
> +	case 168000:
> +		return 0;
> +	case 336000:
> +		return 1;
> +	case 528000:
> +		return 2;
> +	}
> +}

where is the port_clock taking into account?

> +
>  static void cnl_cdclk_pll_update(struct drm_i915_private *dev_priv,
>  				 struct intel_cdclk_state *cdclk_state)
>  {
> @@ -1538,7 +1551,7 @@ static void cnl_get_cdclk(struct drm_i915_private *dev_priv,
>  	cdclk_state->cdclk = cdclk_state->ref;
>  
>  	if (cdclk_state->vco == 0)
> -		return;
> +		goto out;
>  
>  	divider = I915_READ(CDCLK_CTL) & BXT_CDCLK_CD2X_DIV_SEL_MASK;
>  
> @@ -1555,6 +1568,13 @@ static void cnl_get_cdclk(struct drm_i915_private *dev_priv,
>  	}
>  
>  	cdclk_state->cdclk = DIV_ROUND_CLOSEST(cdclk_state->vco, div);
> +
> + out:
> +	/*
> +	 * Can't read this out :( Let's assume it's
> +	 * at least what the CDCLK frequency requires.
> +	 */
> +	cdclk_state->voltage = cnl_calc_voltage(cdclk_state->cdclk);
>  }
>  
>  static void cnl_cdclk_pll_disable(struct drm_i915_private *dev_priv)
> @@ -1595,7 +1615,7 @@ static void cnl_set_cdclk(struct drm_i915_private *dev_priv,
>  {
>  	int cdclk = cdclk_state->cdclk;
>  	int vco = cdclk_state->vco;
> -	u32 val, divider, pcu_ack;
> +	u32 val, divider;
>  	int ret;
>  
>  	mutex_lock(&dev_priv->pcu_lock);
> @@ -1624,19 +1644,6 @@ static void cnl_set_cdclk(struct drm_i915_private *dev_priv,
>  		break;
>  	}
>  
> -	switch (cdclk) {
> -	case 528000:
> -		pcu_ack = 2;
> -		break;
> -	case 336000:
> -		pcu_ack = 1;
> -		break;
> -	case 168000:
> -	default:
> -		pcu_ack = 0;
> -		break;
> -	}
> -
>  	if (dev_priv->cdclk.hw.vco != 0 &&
>  	    dev_priv->cdclk.hw.vco != vco)
>  		cnl_cdclk_pll_disable(dev_priv);
> @@ -1654,7 +1661,8 @@ static void cnl_set_cdclk(struct drm_i915_private *dev_priv,
>  
>  	/* inform PCU of the change */
>  	mutex_lock(&dev_priv->pcu_lock);
> -	sandybridge_pcode_write(dev_priv, SKL_PCODE_CDCLK_CONTROL, pcu_ack);
> +	sandybridge_pcode_write(dev_priv, SKL_PCODE_CDCLK_CONTROL,
> +				cdclk_state->voltage);
>  	mutex_unlock(&dev_priv->pcu_lock);
>  
>  	intel_update_cdclk(dev_priv);
> @@ -1747,6 +1755,7 @@ void cnl_init_cdclk(struct drm_i915_private *dev_priv)
>  
>  	cdclk_state.cdclk = cnl_calc_cdclk(0);
>  	cdclk_state.vco = cnl_cdclk_pll_vco(dev_priv, cdclk_state.cdclk);
> +	cdclk_state.voltage = cnl_calc_voltage(cdclk_state.cdclk);
>  
>  	cnl_set_cdclk(dev_priv, &cdclk_state);
>  }
> @@ -1764,6 +1773,7 @@ void cnl_uninit_cdclk(struct drm_i915_private *dev_priv)
>  
>  	cdclk_state.cdclk = cdclk_state.ref;
>  	cdclk_state.vco = 0;
> +	cdclk_state.voltage = cnl_calc_voltage(cdclk_state.cdclk);
>  
>  	cnl_set_cdclk(dev_priv, &cdclk_state);
>  }
> @@ -2081,6 +2091,7 @@ static int cnl_modeset_calc_cdclk(struct drm_atomic_state *state)
>  
>  	intel_state->cdclk.logical.vco = vco;
>  	intel_state->cdclk.logical.cdclk = cdclk;
> +	intel_state->cdclk.logical.voltage = cnl_calc_voltage(cdclk);
>  
>  	if (!intel_state->active_crtcs) {
>  		cdclk = cnl_calc_cdclk(0);
> @@ -2088,6 +2099,7 @@ static int cnl_modeset_calc_cdclk(struct drm_atomic_state *state)
>  
>  		intel_state->cdclk.actual.vco = vco;
>  		intel_state->cdclk.actual.cdclk = cdclk;
> +		intel_state->cdclk.actual.voltage = cnl_calc_voltage(cdclk);
>  	} else {
>  		intel_state->cdclk.actual =
>  			intel_state->cdclk.logical;
> -- 
> 2.13.6
> 
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