[Intel-gfx] [PATCH 4/4] drm/i915: Determine DP++ type 1 DVI adaptor presence based on VBT
Ville Syrjälä
ville.syrjala at linux.intel.com
Fri Apr 1 14:45:34 UTC 2016
On Thu, Mar 31, 2016 at 10:06:37PM +0000, Zanoni, Paulo R wrote:
> 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.
I don't think it matters much. ILK being the oldest platform with DP++
capable of >165MHz, and at least my ILK here already has VBT version
163. Also this device type stuff was there before 155 already. And
the is_edp() thing has worked for us mostly fine so if we things the
same way it seems unlikely we get too many problems.
>
> - 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.
I'm not sure it's a good idea to trust that some crappy BIOS doesn't
just set whatever random bits on a random port. So a more
conservative approach seems like a better idea to me. Also it matches
how we do the is_edp() check.
>
> - 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);
> > }
--
Ville Syrjälä
Intel OTC
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