[Intel-gfx] [PATCH 3/3] drm/i915: Check live status before reading edid

[Imre Deak]

On Wed, 2015-07-15 at 09:25 +0530, Jindal, Sonika wrote:
> 
> On 7/14/2015 7:59 PM, Imre Deak wrote:
> > On ti, 2015-07-14 at 17:21 +0530, Sonika Jindal wrote:
> >> Adding this for SKL onwards.
> >>
> >> v2: Adding checks for VLV/CHV as well. Reusing old ibx and g4x functions
> >> to check digital port status. Adding a separate function to get bxt live
> >> status (Daniel)
> >>
> >> Signed-off-by: Sonika Jindal <sonika.jindal at intel.com>
> >> ---
> >>   drivers/gpu/drm/i915/intel_dp.c   |    4 ++--
> >>   drivers/gpu/drm/i915/intel_drv.h  |    2 ++
> >>   drivers/gpu/drm/i915/intel_hdmi.c |   43 +++++++++++++++++++++++++++++++++----
> >>   3 files changed, 43 insertions(+), 6 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> >> index 4ebfc3a..7b54b9d 100644
> >> --- a/drivers/gpu/drm/i915/intel_dp.c
> >> +++ b/drivers/gpu/drm/i915/intel_dp.c
> >> @@ -4443,8 +4443,8 @@ ironlake_dp_detect(struct intel_dp *intel_dp)
> >>   	return intel_dp_detect_dpcd(intel_dp);
> >>   }
> >>
> >> -static int g4x_digital_port_connected(struct drm_device *dev,
> >> -				       struct intel_digital_port *intel_dig_port)
> >> +int g4x_digital_port_connected(struct drm_device *dev,
> >> +			       struct intel_digital_port *intel_dig_port)
> >>   {
> >>   	struct drm_i915_private *dev_priv = dev->dev_private;
> >>   	uint32_t bit;
> >> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> >> index a47fbc3..30c8dd6 100644
> >> --- a/drivers/gpu/drm/i915/intel_drv.h
> >> +++ b/drivers/gpu/drm/i915/intel_drv.h
> >> @@ -1187,6 +1187,8 @@ void intel_edp_drrs_disable(struct intel_dp *intel_dp);
> >>   void intel_edp_drrs_invalidate(struct drm_device *dev,
> >>   		unsigned frontbuffer_bits);
> >>   void intel_edp_drrs_flush(struct drm_device *dev, unsigned frontbuffer_bits);
> >> +int g4x_digital_port_connected(struct drm_device *dev,
> >> +			       struct intel_digital_port *intel_dig_port);
> >>
> >>   /* intel_dp_mst.c */
> >>   int intel_dp_mst_encoder_init(struct intel_digital_port *intel_dig_port, int conn_id);
> >> diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
> >> index c4b82ce..402be54 100644
> >> --- a/drivers/gpu/drm/i915/intel_hdmi.c
> >> +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> >> @@ -1300,6 +1300,40 @@ intel_hdmi_unset_edid(struct drm_connector *connector)
> >>   	to_intel_connector(connector)->detect_edid = NULL;
> >>   }
> >>
> >> +static bool bxt_port_connected(struct drm_i915_private *dev_priv,
> >> +			       struct intel_digital_port *port)
> >> +{
> >> +	u32 temp = I915_READ(GEN8_DE_PORT_ISR);
> >> +
> >> +	/* TODO: Add bxt A0/A1 wa related to hpd pin swap */
> >
> > This doesn't seem to work on my BXT A1 RVP. For me GEN8_DE_PORT_ISR
> > reads all 0 even while an HDMI monitor is plugged to port B.
> >
> This is really strange, I checked on atleast 3 different A1 boards and 3 
> different monitors (also on two different branches) and I see 0x44440 as 
> 0x8 after the HPD swap patch when monitor is connected and it is 0 when 
> no hdmi monitor is present.
> Do you think something to do with the board config?

Upgrading my BIOS from version W25 to W29 has solved this issue,
GEN8_DE_PORT_ISR bit 3 is set now correctly whenever the monitor is
connected. My guess is that some GPIO/PIN configuration change done by
the BIOS has fixed this, although I haven't found the reason by looking
at the PAD_CFG register contents and BIOS release notes.


> >> +	switch (port->port) {
> >> +	case PORT_B:
> >> +		return temp & BXT_DE_PORT_HP_DDIB;
> >> +
> >> +	case PORT_C:
> >> +		return temp & BXT_DE_PORT_HP_DDIC;
> >> +
> >> +	default:
> >> +		return false;
> >> +
> >> +	}
> >> +}
> >> +
> >> +static bool intel_hdmi_live_status(struct intel_digital_port *intel_dig_port)
> >> +{
> >> +	struct drm_device *dev = intel_dig_port->base.base.dev;
> >> +	struct drm_i915_private *dev_priv = to_i915(dev);
> >> +
> >> +	if (IS_VALLEYVIEW(dev))
> >> +		return g4x_digital_port_connected(dev, intel_dig_port);
> >> +	else if (IS_SKYLAKE(dev))
> >> +		return ibx_digital_port_connected(dev_priv, intel_dig_port);
> >> +	else if (IS_BROXTON(dev))
> >> +		return bxt_port_connected(dev_priv, intel_dig_port);
> >> +
> >> +	return true;
> >> +}
> >> +
> >>   static bool
> >>   intel_hdmi_set_edid(struct drm_connector *connector)
> >>   {
> >> @@ -1308,15 +1342,16 @@ intel_hdmi_set_edid(struct drm_connector *connector)
> >>   	struct intel_encoder *intel_encoder =
> >>   		&hdmi_to_dig_port(intel_hdmi)->base;
> >>   	enum intel_display_power_domain power_domain;
> >> -	struct edid *edid;
> >> +	struct edid *edid = NULL;
> >>   	bool connected = false;
> >>
> >>   	power_domain = intel_display_port_power_domain(intel_encoder);
> >>   	intel_display_power_get(dev_priv, power_domain);
> >>
> >> -	edid = drm_get_edid(connector,
> >> -			    intel_gmbus_get_adapter(dev_priv,
> >> -						    intel_hdmi->ddc_bus));
> >> +	if (intel_hdmi_live_status(hdmi_to_dig_port(intel_hdmi)))
> >> +		edid = drm_get_edid(connector,
> >> +				intel_gmbus_get_adapter(dev_priv,
> >> +					intel_hdmi->ddc_bus));
> >>
> >>   	intel_display_power_put(dev_priv, power_domain);
> >>
> >
> >