drm/i915: hdmi detection according by reading edid

According to investigations from windows team ,hw team,
and our test results on all 4x platofrms available
(gm45, g45b, q45, g45a, g45c, g41a, and g41), we find
currently Hot plug live status and Hot plug interrupt
detection are not reliable, sometime the results from
the two approaches are contradicts. So we chose edid
detection for hdmi output.
Signed-off-by: Ma Ling <ling.ma@intel.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

drivers/gpu/drm/i915/intel_hdmi.c

@@ -130,16 +130,17 @@ static bool intel_hdmi_mode_fixup(struct drm_encoder *encoder,
 }
 
 static enum drm_connector_status
-intel_hdmi_edid_detect(struct drm_connector *connector)
+intel_hdmi_detect(struct drm_connector *connector)
 {
 	struct intel_output *intel_output = to_intel_output(connector);
 	struct intel_hdmi_priv *hdmi_priv = intel_output->dev_priv;
 	struct edid *edid = NULL;
 	enum drm_connector_status status = connector_status_disconnected;
 
+	hdmi_priv->has_hdmi_sink = false;
 	edid = drm_get_edid(&intel_output->base,
 			    intel_output->ddc_bus);
-	hdmi_priv->has_hdmi_sink = false;
+
 	if (edid) {
 		if (edid->input & DRM_EDID_INPUT_DIGITAL) {
 			status = connector_status_connected;
@@ -148,65 +149,8 @@ intel_hdmi_edid_detect(struct drm_connector *connector)
 		intel_output->base.display_info.raw_edid = NULL;
 		kfree(edid);
 	}
-	return status;
-}
-
-static enum drm_connector_status
-igdng_hdmi_detect(struct drm_connector *connector)
-{
-	struct intel_output *intel_output = to_intel_output(connector);
-	struct intel_hdmi_priv *hdmi_priv = intel_output->dev_priv;
-
-	/* FIXME hotplug detect */
-
-	hdmi_priv->has_hdmi_sink = false;
-	return intel_hdmi_edid_detect(connector);
-}
 
-static enum drm_connector_status
-intel_hdmi_detect(struct drm_connector *connector)
-{
-	struct drm_device *dev = connector->dev;
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct intel_output *intel_output = to_intel_output(connector);
-	struct intel_hdmi_priv *hdmi_priv = intel_output->dev_priv;
-	u32 temp, bit;
-
-	if (IS_IGDNG(dev))
-		return igdng_hdmi_detect(connector);
-
-	temp = I915_READ(PORT_HOTPLUG_EN);
-
-	switch (hdmi_priv->sdvox_reg) {
-	case SDVOB:
-		temp |= HDMIB_HOTPLUG_INT_EN;
-		break;
-	case SDVOC:
-		temp |= HDMIC_HOTPLUG_INT_EN;
-		break;
-	default:
-		return connector_status_unknown;
-	}
-
-	I915_WRITE(PORT_HOTPLUG_EN, temp);
-
-	POSTING_READ(PORT_HOTPLUG_EN);
-
-	switch (hdmi_priv->sdvox_reg) {
-	case SDVOB:
-		bit = HDMIB_HOTPLUG_INT_STATUS;
-		break;
-	case SDVOC:
-		bit = HDMIC_HOTPLUG_INT_STATUS;
-		break;
-	default:
-		return connector_status_unknown;
-	}
-
-	if ((I915_READ(PORT_HOTPLUG_STAT) & bit) != 0)
-		return intel_hdmi_edid_detect(connector);
-	else
-		return connector_status_disconnected;
+	return status;
 }
 
 static int intel_hdmi_get_modes(struct drm_connector *connector)