[Intel-gfx] [PATCH 4/4] drm/i915: Determine DP++ type 1 DVI adaptor presence based on VBT

Zanoni, Paulo R paulo.r.zanoni at intel.com
Thu Mar 31 22:06:37 UTC 2016


Em Ter, 2016-02-23 às 18:46 +0200, ville.syrjala at linux.intel.com
escreveu:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> DP dual mode type 1 DVI adaptors aren't required to implement any
> registers, so it's a bit hard to detect them. The best way would
> be to check the state of the CONFIG1 pin, but we have no way to
> do that. So as a last resort, check the VBT to see if the HDMI
> port is in fact a dual mode capable DP port.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_bios.h |  3 +++
>  drivers/gpu/drm/i915/intel_dp.c   | 28 ++++++++++++++++++++++++++++
>  drivers/gpu/drm/i915/intel_drv.h  |  1 +
>  drivers/gpu/drm/i915/intel_hdmi.c | 23 +++++++++++++++++++++--
>  4 files changed, 53 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_bios.h
> b/drivers/gpu/drm/i915/intel_bios.h
> index 350d4e0f75a4..50d1659efe47 100644
> --- a/drivers/gpu/drm/i915/intel_bios.h
> +++ b/drivers/gpu/drm/i915/intel_bios.h
> @@ -730,6 +730,7 @@ struct bdb_psr {
>  #define	 DEVICE_TYPE_INT_TV	0x1009
>  #define	 DEVICE_TYPE_HDMI	0x60D2
>  #define	 DEVICE_TYPE_DP		0x68C6
> +#define	 DEVICE_TYPE_DP_DUAL_MODE	0x60D6
>  #define	 DEVICE_TYPE_eDP	0x78C6
>  
>  #define  DEVICE_TYPE_CLASS_EXTENSION	(1 << 15)
> @@ -764,6 +765,8 @@ struct bdb_psr {
>  	 DEVICE_TYPE_DISPLAYPORT_OUTPUT | \
>  	 DEVICE_TYPE_ANALOG_OUTPUT)
>  
> +#define DEVICE_TYPE_DP_DUAL_MODE_BITS ~DEVICE_TYPE_NOT_HDMI_OUTPUT
> +
>  /* define the DVO port for HDMI output type */
>  #define		DVO_B		1
>  #define		DVO_C		2
> diff --git a/drivers/gpu/drm/i915/intel_dp.c
> b/drivers/gpu/drm/i915/intel_dp.c
> index cbc06596659a..f3edacf517ac 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -5104,6 +5104,34 @@ bool intel_dp_is_edp(struct drm_device *dev,
> enum port port)
>  	return false;
>  }
>  
> +bool intel_dp_is_dual_mode(struct drm_i915_private *dev_priv, enum
> port port)
> +{
> +	const union child_device_config *p_child;
> +	int i;
> +	static const short port_mapping[] = {
> +		[PORT_B] = DVO_PORT_DPB,
> +		[PORT_C] = DVO_PORT_DPC,
> +		[PORT_D] = DVO_PORT_DPD,
> +		[PORT_E] = DVO_PORT_DPE,
> +	};
> +
> +	if (port == PORT_A || port >= ARRAY_SIZE(port_mapping))
> +		return false;
> +
> +	if (!dev_priv->vbt.child_dev_num)
> +		return false;
> +
> +	for (i = 0; i < dev_priv->vbt.child_dev_num; i++) {
> +		p_child = &dev_priv->vbt.child_dev[i];
> +
> +		if (p_child->common.dvo_port == port_mapping[port]
> &&
> +		    (p_child->common.device_type &
> DEVICE_TYPE_DP_DUAL_MODE_BITS) ==
> +		    (DEVICE_TYPE_DP_DUAL_MODE &
> DEVICE_TYPE_DP_DUAL_MODE_BITS))
> +			return true;
> +	}

Some thoughts:

This is going to be implemented for all VBT versions. Since there's no
real history about anything before version 155, is this really what we
want? A huge part of the "we don't trust the VBT" culture we have on
our team is because of those old versions being completely unreliable.
If this is the case, we could make this implementation just be a small
patch in parse_ddi_port(). I'm kinda afraid we may somehow break old
machines yet again.

- Instead of creating these complicated bit masks, why don't we just
specifically check "if bit 2 and bit 4 are enabled, we're using an
adaptor"? Much simpler IMHO.

- Jani's recent patch suggests you may want to move this function to
intel_bios.c in order to avoid including intel_vbt_defs.h from
intel_hdmi.c. Anyway, you'll have to rebase.

> +	return false;
> +}
> +
>  void
>  intel_dp_add_properties(struct intel_dp *intel_dp, struct
> drm_connector *connector)
>  {
> diff --git a/drivers/gpu/drm/i915/intel_drv.h
> b/drivers/gpu/drm/i915/intel_drv.h
> index 3ca29a181e64..c7d1ea4dbe42 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -1248,6 +1248,7 @@ int intel_dp_sink_crc(struct intel_dp
> *intel_dp, u8 *crc);
>  bool intel_dp_compute_config(struct intel_encoder *encoder,
>  			     struct intel_crtc_state *pipe_config);
>  bool intel_dp_is_edp(struct drm_device *dev, enum port port);
> +bool intel_dp_is_dual_mode(struct drm_i915_private *dev_priv, enum
> port port);
>  enum irqreturn intel_dp_hpd_pulse(struct intel_digital_port
> *intel_dig_port,
>  				  bool long_hpd);
>  void intel_edp_backlight_on(struct intel_dp *intel_dp);
> diff --git a/drivers/gpu/drm/i915/intel_hdmi.c
> b/drivers/gpu/drm/i915/intel_hdmi.c
> index 660a65f48fd8..1476f3afb7e2 100644
> --- a/drivers/gpu/drm/i915/intel_hdmi.c
> +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> @@ -1390,14 +1390,33 @@ intel_hdmi_unset_edid(struct drm_connector
> *connector)
>  }
>  
>  static void
> -intel_hdmi_dp_dual_mode_detect(struct drm_connector *connector)
> +intel_hdmi_dp_dual_mode_detect(struct drm_connector *connector, bool
> has_edid)
>  {
>  	struct drm_i915_private *dev_priv = to_i915(connector->dev);
>  	struct intel_hdmi *hdmi = intel_attached_hdmi(connector);
> +	enum port port = hdmi_to_dig_port(hdmi)->port;
>  	struct i2c_adapter *adapter =
>  		intel_gmbus_get_adapter(dev_priv, hdmi->ddc_bus);
>  	enum drm_dp_dual_mode_type type =
> drm_dp_dual_mode_detect(adapter);
>  
> +	/*
> +	 * Type 1 DVI adaptors are not required to implement any
> +	 * registers, so we can't always detect their presence.
> +	 * Ideally we should be able to check the state of the
> +	 * CONFIG1 pin, but no such luck on our hardware.
> +	 *
> +	 * The only method left to us is to check the VBT to see
> +	 * if the port is a dual mode capable DP port. But let's
> +	 * only do that when we sucesfully read the EDID, to avoid
> +	 * confusing log messages about DP dual mode adaptors when
> +	 * there's nothing connected to the port.
> +	 */
> +	if (type == DRM_DP_DUAL_MODE_NONE && has_edid &&
> +	    intel_dp_is_dual_mode(dev_priv, port)) {
> +		DRM_DEBUG_KMS("Assuming DP dual mode adaptor
> presence based on VBT\n");
> +		type = DRM_DP_DUAL_MODE_TYPE1_DVI;
> +	}
> +
>  	if (type == DRM_DP_DUAL_MODE_NONE)
>  		return;
>  
> @@ -1441,7 +1460,7 @@ intel_hdmi_set_edid(struct drm_connector
> *connector, bool force)
>  				    intel_gmbus_get_adapter(dev_priv
> ,
>  				    intel_hdmi->ddc_bus));
>  
> -		intel_hdmi_dp_dual_mode_detect(connector);
> +		intel_hdmi_dp_dual_mode_detect(connector, edid !=
> NULL);
>  
>  		intel_display_power_put(dev_priv,
> POWER_DOMAIN_GMBUS);
>  	}


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