drm/radeon/kms: don't poll dac load detect.

This is slightly destructive, cpu intensive and can cause lockups.
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/radeon_connectors.c

@@ -663,6 +663,11 @@ radeon_vga_detect(struct drm_connector *connector, bool force)
 				ret = connector_status_connected;
 		}
 	} else {
+
+		/* if we aren't forcing don't do destructive polling */
+		if (!force)
+			return connector->status;
+
 		if (radeon_connector->dac_load_detect && encoder) {
 			encoder_funcs = encoder->helper_private;
 			ret = encoder_funcs->detect(encoder, connector);
@@ -850,6 +855,11 @@ radeon_dvi_detect(struct drm_connector *connector, bool force)
 	if ((ret == connector_status_connected) && (radeon_connector->use_digital == true))
 		goto out;
 
+	if (!force) {
+		ret = connector->status;
+		goto out;
+	}
+
 	/* find analog encoder */
 	if (radeon_connector->dac_load_detect) {
 		for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++) {