diff --git a/sys/bus/smbus/ichiic/ig4_iic.c b/sys/bus/smbus/ichiic/ig4_iic.c
--- a/sys/bus/smbus/ichiic/ig4_iic.c
+++ b/sys/bus/smbus/ichiic/ig4_iic.c
@@ -651,6 +651,7 @@
 	if (error) {
 		device_printf(sc->dev,
 			      "Unable to setup irq: error %d\n", error);
+		lwkt_serialize_exit(&sc->slz);
 		goto done;
 	}