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

On Fri, 01 Apr 2016, "Zanoni, Paulo R" paulo.r.zanoni@intel.com wrote:

Em Ter, 2016-02-23 às 18:46 +0200, ville.syrjala@linux.intel.com escreveu:

...

From: Ville Syrjälä ville.syrjala@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@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.

Yup, it should become intel_bios_is_dp_dual_mode() or something along those lines in intel_bios.c. intel_vbt_defs.h is now private data to intel_bios.c. intel_bios.h should be kept minimal.

My long term plan is to make most of dev_priv->vbt opaque pointers you can query using helpers provided by intel_bios.c. In the future, this should make it easier to change how we obtain and store the data. This should also make it easier to handle setups without VBT or with limited VBT.

BR, Jani.

...

• 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);   }