[Intel-gfx] [PATCH 1/4] drm/i915: Remove redundant toggling from the power well sync_hw hooks

[Ander Conselvan De Oliveira]

On Wed, 2017-02-15 at 13:59 +0200, Imre Deak wrote:
> Doing an explicit enable/disable in the power well sync_hw hook based on
> the power well's reference count is redundant, since by the time these
> hooks are called all the power wells are enabled and have a reference.
> So remove the redundant toggling.
> 
> This is needed by a follow-up patchset that adds power wells which we
> can't enable/disable during power domain initialization and so want to
> preserve their state until modeset init time.
> 
> Cc: Ander Conselvan de Oliveira <conselvan2 at gmail.com>
> Cc: David Weinehall <david.weinehall at linux.intel.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Signed-off-by: Imre Deak <imre.deak at intel.com>

Reviewed-by: Ander Conselvan de Oliveira <conselvan2 at gmail.com>

> ---
>  drivers/gpu/drm/i915/intel_runtime_pm.c | 52 +++++++-------------------------
> -
>  1 file changed, 10 insertions(+), 42 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c
> b/drivers/gpu/drm/i915/intel_runtime_pm.c
> index 8795679..0f64bc1 100644
> --- a/drivers/gpu/drm/i915/intel_runtime_pm.c
> +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
> @@ -847,8 +847,6 @@ static void skl_set_power_well(struct drm_i915_private
> *dev_priv,
>  static void hsw_power_well_sync_hw(struct drm_i915_private *dev_priv,
>  				   struct i915_power_well *power_well)
>  {
> -	hsw_set_power_well(dev_priv, power_well, power_well->count > 0);
> -
>  	/*
>  	 * We're taking over the BIOS, so clear any requests made by it since
>  	 * the driver is in charge now.
> @@ -881,8 +879,6 @@ static bool skl_power_well_enabled(struct drm_i915_private
> *dev_priv,
>  static void skl_power_well_sync_hw(struct drm_i915_private *dev_priv,
>  				struct i915_power_well *power_well)
>  {
> -	skl_set_power_well(dev_priv, power_well, power_well->count > 0);
> -
>  	/* Clear any request made by BIOS as driver is taking over */
>  	I915_WRITE(HSW_PWR_WELL_BIOS, 0);
>  }
> @@ -917,16 +913,6 @@ static bool bxt_dpio_cmn_power_well_enabled(struct
> drm_i915_private *dev_priv,
>  	return bxt_ddi_phy_is_enabled(dev_priv, power_well->data);
>  }
>  
> -static void bxt_dpio_cmn_power_well_sync_hw(struct drm_i915_private
> *dev_priv,
> -					    struct i915_power_well
> *power_well)
> -{
> -	if (power_well->count > 0)
> -		bxt_dpio_cmn_power_well_enable(dev_priv, power_well);
> -	else
> -		bxt_dpio_cmn_power_well_disable(dev_priv, power_well);
> -}
> -
> -
>  static void bxt_verify_ddi_phy_power_wells(struct drm_i915_private *dev_priv)
>  {
>  	struct i915_power_well *power_well;
> @@ -989,13 +975,9 @@ static void gen9_dc_off_power_well_disable(struct
> drm_i915_private *dev_priv,
>  		gen9_enable_dc5(dev_priv);
>  }
>  
> -static void gen9_dc_off_power_well_sync_hw(struct drm_i915_private *dev_priv,
> -					   struct i915_power_well
> *power_well)
> +static void i9xx_power_well_sync_hw_noop(struct drm_i915_private *dev_priv,
> +					 struct i915_power_well *power_well)
>  {
> -	if (power_well->count > 0)
> -		gen9_dc_off_power_well_enable(dev_priv, power_well);
> -	else
> -		gen9_dc_off_power_well_disable(dev_priv, power_well);
>  }
>  
>  static void i9xx_always_on_power_well_noop(struct drm_i915_private *dev_priv,
> @@ -1045,12 +1027,6 @@ static void vlv_set_power_well(struct drm_i915_private
> *dev_priv,
>  	mutex_unlock(&dev_priv->rps.hw_lock);
>  }
>  
> -static void vlv_power_well_sync_hw(struct drm_i915_private *dev_priv,
> -				   struct i915_power_well *power_well)
> -{
> -	vlv_set_power_well(dev_priv, power_well, power_well->count > 0);
> -}
> -
>  static void vlv_power_well_enable(struct drm_i915_private *dev_priv,
>  				  struct i915_power_well *power_well)
>  {
> @@ -1661,14 +1637,6 @@ static void chv_set_pipe_power_well(struct
> drm_i915_private *dev_priv,
>  	mutex_unlock(&dev_priv->rps.hw_lock);
>  }
>  
> -static void chv_pipe_power_well_sync_hw(struct drm_i915_private *dev_priv,
> -					struct i915_power_well *power_well)
> -{
> -	WARN_ON_ONCE(power_well->id != PIPE_A);
> -
> -	chv_set_pipe_power_well(dev_priv, power_well, power_well->count > 0);
> -}
> -
>  static void chv_pipe_power_well_enable(struct drm_i915_private *dev_priv,
>  				       struct i915_power_well *power_well)
>  {
> @@ -1914,21 +1882,21 @@ void intel_display_power_put(struct drm_i915_private
> *dev_priv,
>  	BIT_ULL(POWER_DOMAIN_INIT))
>  
>  static const struct i915_power_well_ops i9xx_always_on_power_well_ops = {
> -	.sync_hw = i9xx_always_on_power_well_noop,
> +	.sync_hw = i9xx_power_well_sync_hw_noop,
>  	.enable = i9xx_always_on_power_well_noop,
>  	.disable = i9xx_always_on_power_well_noop,
>  	.is_enabled = i9xx_always_on_power_well_enabled,
>  };
>  
>  static const struct i915_power_well_ops chv_pipe_power_well_ops = {
> -	.sync_hw = chv_pipe_power_well_sync_hw,
> +	.sync_hw = i9xx_power_well_sync_hw_noop,
>  	.enable = chv_pipe_power_well_enable,
>  	.disable = chv_pipe_power_well_disable,
>  	.is_enabled = chv_pipe_power_well_enabled,
>  };
>  
>  static const struct i915_power_well_ops chv_dpio_cmn_power_well_ops = {
> -	.sync_hw = vlv_power_well_sync_hw,
> +	.sync_hw = i9xx_power_well_sync_hw_noop,
>  	.enable = chv_dpio_cmn_power_well_enable,
>  	.disable = chv_dpio_cmn_power_well_disable,
>  	.is_enabled = vlv_power_well_enabled,
> @@ -1958,14 +1926,14 @@ static const struct i915_power_well_ops
> skl_power_well_ops = {
>  };
>  
>  static const struct i915_power_well_ops gen9_dc_off_power_well_ops = {
> -	.sync_hw = gen9_dc_off_power_well_sync_hw,
> +	.sync_hw = i9xx_power_well_sync_hw_noop,
>  	.enable = gen9_dc_off_power_well_enable,
>  	.disable = gen9_dc_off_power_well_disable,
>  	.is_enabled = gen9_dc_off_power_well_enabled,
>  };
>  
>  static const struct i915_power_well_ops bxt_dpio_cmn_power_well_ops = {
> -	.sync_hw = bxt_dpio_cmn_power_well_sync_hw,
> +	.sync_hw = i9xx_power_well_sync_hw_noop,
>  	.enable = bxt_dpio_cmn_power_well_enable,
>  	.disable = bxt_dpio_cmn_power_well_disable,
>  	.is_enabled = bxt_dpio_cmn_power_well_enabled,
> @@ -2000,21 +1968,21 @@ static struct i915_power_well bdw_power_wells[] = {
>  };
>  
>  static const struct i915_power_well_ops vlv_display_power_well_ops = {
> -	.sync_hw = vlv_power_well_sync_hw,
> +	.sync_hw = i9xx_power_well_sync_hw_noop,
>  	.enable = vlv_display_power_well_enable,
>  	.disable = vlv_display_power_well_disable,
>  	.is_enabled = vlv_power_well_enabled,
>  };
>  
>  static const struct i915_power_well_ops vlv_dpio_cmn_power_well_ops = {
> -	.sync_hw = vlv_power_well_sync_hw,
> +	.sync_hw = i9xx_power_well_sync_hw_noop,
>  	.enable = vlv_dpio_cmn_power_well_enable,
>  	.disable = vlv_dpio_cmn_power_well_disable,
>  	.is_enabled = vlv_power_well_enabled,
>  };
>  
>  static const struct i915_power_well_ops vlv_dpio_power_well_ops = {
> -	.sync_hw = vlv_power_well_sync_hw,
> +	.sync_hw = i9xx_power_well_sync_hw_noop,
>  	.enable = vlv_power_well_enable,
>  	.disable = vlv_power_well_disable,
>  	.is_enabled = vlv_power_well_enabled,