Re: [PATCH 10/11] drm/i915: Move VLV cmnlane workaround to intel_power_domains_init_hw()

[Jesse Barnes <jbarnes@virtuousgeek.org>]

On Fri, 13 Jun 2014 13:37:56 +0300
ville.syrjala@linux.intel.com wrote:

> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> Now that the CMNRESET deassert is part of the cmnlane power well,
> intel_reset_dpio() is called too late to make any difference. We've
> deasserted CMNRESET by that time, and so the off+on toggle w/a will
> never kick in.
> 
> Move the workaround to intel_power_domains_init_hw() where it gets
> called before we enable the init power domain.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c | 23 -------------
>  drivers/gpu/drm/i915/intel_drv.h     |  3 +-
>  drivers/gpu/drm/i915/intel_pm.c      | 67 ++++++++++++++++++++++++++++++------
>  3 files changed, 58 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 33cc213..bcd32322 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -1508,9 +1508,6 @@ static void intel_reset_dpio(struct drm_device *dev)
>  {
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  
> -	if (!IS_VALLEYVIEW(dev))
> -		return;
> -
>  	if (IS_CHERRYVIEW(dev)) {
>  		enum dpio_phy phy;
>  		u32 val;
> @@ -1532,26 +1529,6 @@ static void intel_reset_dpio(struct drm_device *dev)
>  			I915_WRITE(DISPLAY_PHY_CONTROL,
>  				PHY_COM_LANE_RESET_DEASSERT(phy, val));
>  		}
> -
> -	} else {
> -		/*
> -		 * If DPIO has already been reset, e.g. by BIOS, just skip all
> -		 * this.
> -		 */
> -		if (I915_READ(DPIO_CTL) & DPIO_CMNRST)
> -			return;
> -
> -		/*
> -		 * From VLV2A0_DP_eDP_HDMI_DPIO_driver_vbios_notes_11.docx:
> -		 * Need to assert and de-assert PHY SB reset by gating the
> -		 * common lane power, then un-gating it.
> -		 * Simply ungating isn't enough to reset the PHY enough to get
> -		 * ports and lanes running.
> -		 */
> -		__vlv_set_power_well(dev_priv, PUNIT_POWER_WELL_DPIO_CMN_BC,
> -				     false);
> -		__vlv_set_power_well(dev_priv, PUNIT_POWER_WELL_DPIO_CMN_BC,
> -				     true);
>  	}
>  }
>  
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 5740be0..e565906 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -970,8 +970,7 @@ void intel_runtime_pm_put(struct drm_i915_private *dev_priv);
>  void intel_init_runtime_pm(struct drm_i915_private *dev_priv);
>  void intel_fini_runtime_pm(struct drm_i915_private *dev_priv);
>  void ilk_wm_get_hw_state(struct drm_device *dev);
> -void __vlv_set_power_well(struct drm_i915_private *dev_priv,
> -			  enum punit_power_well power_well_id, bool enable);
> +
>  
>  /* intel_sdvo.c */
>  bool intel_sdvo_init(struct drm_device *dev, uint32_t sdvo_reg, bool is_sdvob);
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index e9a8565..d8e20d3 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -5962,9 +5962,10 @@ static bool i9xx_always_on_power_well_enabled(struct drm_i915_private *dev_priv,
>  	return true;
>  }
>  
> -void __vlv_set_power_well(struct drm_i915_private *dev_priv,
> -			  enum punit_power_well power_well_id, bool enable)
> +static void vlv_set_power_well(struct drm_i915_private *dev_priv,
> +			       struct i915_power_well *power_well, bool enable)
>  {
> +	enum punit_power_well power_well_id = power_well->data;
>  	u32 mask;
>  	u32 state;
>  	u32 ctrl;
> @@ -5997,14 +5998,6 @@ out:
>  	mutex_unlock(&dev_priv->rps.hw_lock);
>  }
>  
> -static void vlv_set_power_well(struct drm_i915_private *dev_priv,
> -			       struct i915_power_well *power_well, bool enable)
> -{
> -	enum punit_power_well power_well_id = power_well->data;
> -
> -	__vlv_set_power_well(dev_priv, power_well_id, enable);
> -}
> -
>  static void vlv_power_well_sync_hw(struct drm_i915_private *dev_priv,
>  				   struct i915_power_well *power_well)
>  {
> @@ -6435,6 +6428,21 @@ static struct i915_power_well vlv_power_wells[] = {
>  	},
>  };
>  
> +static struct i915_power_well *lookup_power_well(struct drm_i915_private *dev_priv,
> +						 enum punit_power_well power_well_id)
> +{
> +	struct i915_power_domains *power_domains = &dev_priv->power_domains;
> +	struct i915_power_well *power_well;
> +	int i;
> +
> +	for_each_power_well(i, power_well, POWER_DOMAIN_MASK, power_domains) {
> +		if (power_well->data == power_well_id)
> +			return power_well;
> +	}
> +
> +	return NULL;
> +}
> +
>  #define set_power_wells(power_domains, __power_wells) ({		\
>  	(power_domains)->power_wells = (__power_wells);			\
>  	(power_domains)->power_well_count = ARRAY_SIZE(__power_wells);	\
> @@ -6482,11 +6490,50 @@ static void intel_power_domains_resume(struct drm_i915_private *dev_priv)
>  	mutex_unlock(&power_domains->lock);
>  }
>  
> +static void vlv_cmnlane_wa(struct drm_i915_private *dev_priv)
> +{
> +	struct i915_power_well *cmn =
> +		lookup_power_well(dev_priv, PUNIT_POWER_WELL_DPIO_CMN_BC);
> +	struct i915_power_well *disp2d =
> +		lookup_power_well(dev_priv, PUNIT_POWER_WELL_DISP2D);
> +
> +	/* nothing to do if common lane is already off */
> +	if (!cmn->ops->is_enabled(dev_priv, cmn))
> +		return;
> +
> +	/* If the display might be already active skip this */
> +	if (disp2d->ops->is_enabled(dev_priv, disp2d) &&
> +	    I915_READ(DPIO_CTL) & DPIO_CMNRST)
> +		return;
> +
> +	DRM_DEBUG_KMS("toggling display PHY side reset\n");
> +
> +	/* cmnlane needs DPLL registers */
> +	disp2d->ops->enable(dev_priv, disp2d);
> +
> +	/*
> +	 * From VLV2A0_DP_eDP_HDMI_DPIO_driver_vbios_notes_11.docx:
> +	 * Need to assert and de-assert PHY SB reset by gating the
> +	 * common lane power, then un-gating it.
> +	 * Simply ungating isn't enough to reset the PHY enough to get
> +	 * ports and lanes running.
> +	 */
> +	cmn->ops->disable(dev_priv, cmn);
> +}
> +
>  void intel_power_domains_init_hw(struct drm_i915_private *dev_priv)
>  {
> +	struct drm_device *dev = dev_priv->dev;
>  	struct i915_power_domains *power_domains = &dev_priv->power_domains;
>  
>  	power_domains->initializing = true;
> +
> +	if (IS_VALLEYVIEW(dev) && !IS_CHERRYVIEW(dev)) {
> +		mutex_lock(&power_domains->lock);
> +		vlv_cmnlane_wa(dev_priv);
> +		mutex_unlock(&power_domains->lock);
> +	}
> +
>  	/* For now, we need the power well to be always enabled. */
>  	intel_display_set_init_power(dev_priv, true);
>  	intel_power_domains_resume(dev_priv);

I kind of preferred the low level function that just took a well ID
directly since the idea of looking something we already know seems
silly (and it should probably be a separate patch anyway). Also I'm not
sure I would describe this as a W/A; the phy needs to get reset
somehow...

But with or without those changes, we need this.

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>

-- 
Jesse Barnes, Intel Open Source Technology Center
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