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

[Sonika Jindal]

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 |   42 +++++++++++++++++++++++++++++++++----
 3 files changed, 42 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 1fb6919..7eb0d0e 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -1300,6 +1300,39 @@ 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);
+
+	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 +1341,16 @@ 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);
 
-- 
1.7.10.4