[Intel-gfx] [PATCH] drm/i915/crt: Keep the EDID for the whole detect cycle

[Imre Deak]

On to, 2016-09-29 at 11:52 +0100, Chris Wilson wrote:
> Other than reducing the number of EDID reads required for probing the
> modes on a connector, this refactor has the importance of centralising
> the logic for deciding when we need to probe for an analogue output via
> DVI-I and then consistently using that information between detection and
> mode computation.
> 
> References: https://bugs.freedesktop.org/show_bug.cgi?id=97971
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Imre Deak <imre.deak at intel.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>

kfree(detect_edid) during connector destroy.
Also shouldn't connector forcing also force rereading the EDID?

Otherwise looks ok to me.

> ---
>  drivers/gpu/drm/i915/intel_crt.c | 98 +++++++++++++++-------------------------
>  1 file changed, 36 insertions(+), 62 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c
> index 88ebbdde185a..b9b88b0b73e7 100644
> --- a/drivers/gpu/drm/i915/intel_crt.c
> +++ b/drivers/gpu/drm/i915/intel_crt.c
> @@ -459,8 +459,8 @@ static bool intel_crt_detect_hotplug(struct drm_connector *connector)
>  	return ret;
>  }
>  
> -static struct edid *intel_crt_get_edid(struct drm_connector *connector,
> -				struct i2c_adapter *i2c)
> +static struct edid *__intel_crt_get_edid(struct drm_connector *connector,
> +					 struct i2c_adapter *i2c)
>  {
>  	struct edid *edid;
>  
> @@ -473,59 +473,50 @@ static struct edid *intel_crt_get_edid(struct drm_connector *connector,
>  		intel_gmbus_force_bit(i2c, false);
>  	}
>  
> -	return edid;
> -}
> -
> -/* local version of intel_ddc_get_modes() to use intel_crt_get_edid() */
> -static int intel_crt_ddc_get_modes(struct drm_connector *connector,
> -				struct i2c_adapter *adapter)
> -{
> -	struct edid *edid;
> -	int ret;
> -
> -	edid = intel_crt_get_edid(connector, adapter);
> -	if (!edid)
> -		return 0;
> -
> -	ret = intel_connector_update_modes(connector, edid);
> -	kfree(edid);
> +	if (edid && edid->input & DRM_EDID_INPUT_DIGITAL) {
> +		DRM_DEBUG_KMS("EDID reports a digital output, ignoring for this VGA connector\n");
> +		kfree(edid);
> +		edid = NULL;
> +	}
>  
> -	return ret;
> +	return edid;
>  }
>  
> -static bool intel_crt_detect_ddc(struct drm_connector *connector)
> +static struct edid *intel_crt_get_edid(struct drm_connector *connector)
>  {
> -	struct intel_crt *crt = intel_attached_crt(connector);
> -	struct drm_i915_private *dev_priv = to_i915(crt->base.base.dev);
> -	struct edid *edid;
> +#define HAS_DVI_I(p) 1 /* XXX anything with HDMI, i.e. g33+ */
> +	struct drm_i915_private *dev_priv = to_i915(connector->dev);
>  	struct i2c_adapter *i2c;
> -
> -	BUG_ON(crt->base.type != INTEL_OUTPUT_ANALOG);
> +	struct edid *edid;
>  
>  	i2c = intel_gmbus_get_adapter(dev_priv, dev_priv->vbt.crt_ddc_pin);
> -	edid = intel_crt_get_edid(connector, i2c);
> -
> -	if (edid) {
> -		bool is_digital = edid->input & DRM_EDID_INPUT_DIGITAL;
> -
> +	edid = __intel_crt_get_edid(connector, i2c);
> +	if (!edid && HAS_DVI_I(dev_priv)) {
>  		/*
>  		 * This may be a DVI-I connector with a shared DDC
>  		 * link between analog and digital outputs, so we
>  		 * have to check the EDID input spec of the attached device.
>  		 */
> -		if (!is_digital) {
> -			DRM_DEBUG_KMS("CRT detected via DDC:0x50 [EDID]\n");
> -			return true;
> -		}
> -
> -		DRM_DEBUG_KMS("CRT not detected via DDC:0x50 [EDID reports a digital panel]\n");
> -	} else {
> -		DRM_DEBUG_KMS("CRT not detected via DDC:0x50 [no valid EDID found]\n");
> +		i2c = intel_gmbus_get_adapter(dev_priv, GMBUS_PIN_DPB);
> +		edid = __intel_crt_get_edid(connector, i2c);
>  	}
>  
> -	kfree(edid);
> +	return edid;
> +}
> +
> +static bool intel_crt_detect_ddc(struct drm_connector *connector)
> +{
> +	struct edid *edid;
> +
> +	kfree(to_intel_connector(connector)->detect_edid);
> +	to_intel_connector(connector)->detect_edid = NULL;
>  
> -	return false;
> +	edid = intel_crt_get_edid(connector);
> +	if (!edid)
> +		return false;
> +
> +	to_intel_connector(connector)->detect_edid = edid;
> +	return true;
>  }
>  
>  static enum drm_connector_status
> @@ -727,30 +718,13 @@ static void intel_crt_destroy(struct drm_connector *connector)
>  
>  static int intel_crt_get_modes(struct drm_connector *connector)
>  {
> -	struct drm_device *dev = connector->dev;
> -	struct drm_i915_private *dev_priv = to_i915(dev);
> -	struct intel_crt *crt = intel_attached_crt(connector);
> -	struct intel_encoder *intel_encoder = &crt->base;
> -	enum intel_display_power_domain power_domain;
> -	int ret;
> -	struct i2c_adapter *i2c;
> -
> -	power_domain = intel_display_port_power_domain(intel_encoder);
> -	intel_display_power_get(dev_priv, power_domain);
> -
> -	i2c = intel_gmbus_get_adapter(dev_priv, dev_priv->vbt.crt_ddc_pin);
> -	ret = intel_crt_ddc_get_modes(connector, i2c);
> -	if (ret || !IS_G4X(dev))
> -		goto out;
> -
> -	/* Try to probe digital port for output in DVI-I -> VGA mode. */
> -	i2c = intel_gmbus_get_adapter(dev_priv, GMBUS_PIN_DPB);
> -	ret = intel_crt_ddc_get_modes(connector, i2c);
> +	struct edid *edid;
>  
> -out:
> -	intel_display_power_put(dev_priv, power_domain);
> +	edid = to_intel_connector(connector)->detect_edid;
> +	if (!edid)
> +		return 0;
>  
> -	return ret;
> +	return intel_connector_update_modes(connector, edid);
>  }
>  
>  static int intel_crt_set_property(struct drm_connector *connector,