[Intel-gfx] [PATCH 1/6] drm/i915: Splitting intel_dp_detect

[Ander Conselvan De Oliveira]

On Wed, 2016-01-13 at 13:20 +0200, Ander Conselvan De Oliveira wrote:
> On Tue, 2016-01-05 at 18:20 +0530, Shubhangi Shrivastava wrote:
> > intel_dp_detect() is called for not just detection but
> > during modes enumeration as well. Repeating the whole
> > sequence during each of these calls is wasteful and
> > time consuming.
> > This patch moves probing for panel, DPCD read etc done in
> > intel_dp_detect() to a new function intel_dp_long_pulse().
> > Note that the behavior of intel_dp_detect() is changed to
> > report connected or disconnected depending on whether the
> > EDID is available or not.
> > This change will be required by further patches in the series
> > to avoid performing duplicated DPCD operations on hotplug.
> > 
> > v2: Moved a hunk to next patch of the series.
> >     Moved intel_dp_unset_edid to out. (Ander)
> > v3: Rephrased commit message and intel_dp_unset_dp() is called
> >     within intel_dp_set_dp() to free the previous EDID. (Ander)
> > 
> > Tested-by: Nathan D Ciobanu <nathan.d.ciobanu at intel.com>
> > Signed-off-by: Sivakumar Thulasimani <sivakumar.thulasimani at intel.com>
> > Signed-off-by: Shubhangi Shrivastava <shubhangi.shrivastava at intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_dp.c | 56 +++++++++++++++++++++++++-------------
> > --
> > -
> >  1 file changed, 35 insertions(+), 21 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c
> > b/drivers/gpu/drm/i915/intel_dp.c
> > index 796e3d3..e3b4208 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -129,6 +129,7 @@ static void edp_panel_vdd_off(struct intel_dp *intel_dp,
> > bool sync);
> >  static void vlv_init_panel_power_sequencer(struct intel_dp *intel_dp);
> >  static void vlv_steal_power_sequencer(struct drm_device *dev,
> >  				      enum pipe pipe);
> > +static void intel_dp_unset_edid(struct intel_dp *intel_dp);
> >  
> >  static unsigned int intel_dp_unused_lane_mask(int lane_count)
> >  {
> > @@ -4587,6 +4588,7 @@ intel_dp_set_edid(struct intel_dp *intel_dp)
> >  	struct intel_connector *intel_connector = intel_dp
> > ->attached_connector;
> >  	struct edid *edid;
> >  
> > +	intel_dp_unset_edid(intel_dp);
> >  	edid = intel_dp_get_edid(intel_dp);
> >  	intel_connector->detect_edid = edid;
> >  
> > @@ -4607,9 +4609,10 @@ intel_dp_unset_edid(struct intel_dp *intel_dp)
> >  	intel_dp->has_audio = false;
> >  }
> >  
> > -static enum drm_connector_status
> > -intel_dp_detect(struct drm_connector *connector, bool force)
> > +static void
> > +intel_dp_long_pulse(struct intel_connector *intel_connector)
> >  {
> > +	struct drm_connector *connector = &intel_connector->base;
> >  	struct intel_dp *intel_dp = intel_attached_dp(connector);
> >  	struct intel_digital_port *intel_dig_port =
> > dp_to_dig_port(intel_dp);
> >  	struct intel_encoder *intel_encoder = &intel_dig_port->base;
> > @@ -4619,17 +4622,6 @@ intel_dp_detect(struct drm_connector *connector, bool
> > force)
> >  	bool ret;
> >  	u8 sink_irq_vector;
> >  
> > -	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n",
> > -		      connector->base.id, connector->name);
> > -	intel_dp_unset_edid(intel_dp);
> > -
> > -	if (intel_dp->is_mst) {
> > -		/* MST devices are disconnected from a monitor POV */
> > -		if (intel_encoder->type != INTEL_OUTPUT_EDP)
> > -			intel_encoder->type = INTEL_OUTPUT_DISPLAYPORT;
> > -		return connector_status_disconnected;
> > -	}
> > -
> >  	power_domain = intel_display_port_aux_power_domain(intel_encoder);
> >  	intel_display_power_get(to_i915(dev), power_domain);
> >  
> > @@ -4653,14 +4645,8 @@ intel_dp_detect(struct drm_connector *connector, bool
> > force)
> >  	intel_dp_probe_oui(intel_dp);
> >  
> >  	ret = intel_dp_probe_mst(intel_dp);
> > -	if (ret) {
> > -		/* if we are in MST mode then this connector
> > -		   won't appear connected or have anything with EDID on it
> > */
> > -		if (intel_encoder->type != INTEL_OUTPUT_EDP)
> > -			intel_encoder->type = INTEL_OUTPUT_DISPLAYPORT;
> 
> This deletion is new in this version of the patch. I think we still need the
> hunk above, otherwise we might not properly update the encoder type when we
> switch from an HDMI sink connected through a level shifter to an MST sink.
> 
> Ander
> 
> 
> > -		status = connector_status_disconnected;
> > +	if (ret)
> >  		goto out;

Also, there is no call to intel_dp_unset_edid() for this case, since the code
will reach the label 'out' with status being connected. So in this case the
return value of intel_dp_detect() will depend on the stale value of
intel_dp->detect_edid.

Ander

> > -	}
> >  
> >  	/*
> >  	 * Clearing NACK and defer counts to get their exact values
> > @@ -4691,8 +4677,36 @@ intel_dp_detect(struct drm_connector *connector, bool
> > force)
> >  	}
> >  
> >  out:
> > +	if (status != connector_status_connected)
> > +		intel_dp_unset_edid(intel_dp);
> >  	intel_display_power_put(to_i915(dev), power_domain);
> > -	return status;
> > +	return;
> > +}
> > +
> > +static enum drm_connector_status
> > +intel_dp_detect(struct drm_connector *connector, bool force)
> > +{
> > +	struct intel_dp *intel_dp = intel_attached_dp(connector);
> > +	struct intel_digital_port *intel_dig_port =
> > dp_to_dig_port(intel_dp);
> > +	struct intel_encoder *intel_encoder = &intel_dig_port->base;
> > +	struct intel_connector *intel_connector =
> > to_intel_connector(connector);
> > +
> > +	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n",
> > +		     connector->base.id, connector->name);
> > +
> > +	if (intel_dp->is_mst) {
> > +		/* MST devices are disconnected from a monitor POV */
> > +		if (intel_encoder->type != INTEL_OUTPUT_EDP)
> > +			intel_encoder->type = INTEL_OUTPUT_DISPLAYPORT;
> > +		return connector_status_disconnected;
> > +	}
> > +
> > +	intel_dp_long_pulse(intel_dp->attached_connector);
> > +
> > +	if (intel_connector->detect_edid)
> > +		return connector_status_connected;
> > +	else
> > +		return connector_status_disconnected;
> >  }
> >  
> >  static void