drm/i915/hdmi: Query the live connector status bit for G4x

Similar to g4x_dp_detect() we should probe the PORT_HOTPLUG_STATUS as to
whether the connector is active prior to attempting to retrieve the EDID.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_hdmi.c

@@ -452,6 +452,30 @@ static bool intel_hdmi_mode_fixup(struct drm_encoder *encoder,
 	return true;
 }
 
+static bool g4x_hdmi_connected(struct intel_hdmi *intel_hdmi)
+{
+	struct drm_device *dev = intel_hdmi->base.base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	uint32_t bit;
+
+	switch (intel_hdmi->sdvox_reg) {
+	case HDMIB:
+		bit = HDMIB_HOTPLUG_LIVE_STATUS;
+		break;
+	case HDMIC:
+		bit = HDMIC_HOTPLUG_LIVE_STATUS;
+		break;
+	case HDMID:
+		bit = HDMID_HOTPLUG_LIVE_STATUS;
+		break;
+	default:
+		bit = 0;
+		break;
+	}
+
+	return I915_READ(PORT_HOTPLUG_STAT) & bit;
+}
+
 static enum drm_connector_status
 intel_hdmi_detect(struct drm_connector *connector, bool force)
 {
@@ -460,6 +484,9 @@ intel_hdmi_detect(struct drm_connector *connector, bool force)
 	struct edid *edid;
 	enum drm_connector_status status = connector_status_disconnected;
 
+	if (IS_G4X(connector->dev) && !g4x_hdmi_connected(intel_hdmi))
+		return status;
+
 	intel_hdmi->has_hdmi_sink = false;
 	intel_hdmi->has_audio = false;
 	edid = drm_get_edid(connector,