drm/i915: Skip SDVO/HDMI init when the chipset tells us it's not present.

This saves startup time from probing SDVO, and saves setting up HDMI outputs
on G4X devices that don't have them.
Signed-off-by: Dave Airlie <airlied@linux.ie>

drivers/gpu/drm/i915/intel_display.c

@@ -1452,6 +1452,7 @@ static int intel_connector_clones(struct drm_device *dev, int type_mask)
 
 static void intel_setup_outputs(struct drm_device *dev)
 {
+	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct drm_connector *connector;
 
 	intel_crt_init(dev);
@@ -1463,13 +1464,16 @@ static void intel_setup_outputs(struct drm_device *dev)
 	if (IS_I9XX(dev)) {
 		int found;
 
-		found = intel_sdvo_init(dev, SDVOB);
-		if (!found && SUPPORTS_INTEGRATED_HDMI(dev))
-			intel_hdmi_init(dev, SDVOB);
-
-		found = intel_sdvo_init(dev, SDVOC);
-		if (!found && SUPPORTS_INTEGRATED_HDMI(dev))
-			intel_hdmi_init(dev, SDVOC);
+		if (I915_READ(SDVOB) & SDVO_DETECTED) {
+			found = intel_sdvo_init(dev, SDVOB);
+			if (!found && SUPPORTS_INTEGRATED_HDMI(dev))
+				intel_hdmi_init(dev, SDVOB);
+		}
+		if (!IS_G4X(dev) || (I915_READ(SDVOB) & SDVO_DETECTED)) {
+			found = intel_sdvo_init(dev, SDVOC);
+			if (!found && SUPPORTS_INTEGRATED_HDMI(dev))
+				intel_hdmi_init(dev, SDVOC);
+		}
 	} else
 		intel_dvo_init(dev);