diff --git a/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/Controller.java b/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/Controller.java
index 882b75a..5b0c8ac 100644
--- a/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/Controller.java
+++ b/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/Controller.java
@@ -207,7 +207,7 @@
         Driver driver = driverService
                 .getDriver(desc.getMfrDesc(), desc.getHwDesc(), desc.getSwDesc());
 
-        if (driver.hasBehaviour(OpenFlowSwitchDriver.class)) {
+        if (driver != null && driver.hasBehaviour(OpenFlowSwitchDriver.class)) {
             OpenFlowSwitchDriver ofSwitchDriver = driver.createBehaviour(new DefaultDriverHandler(
                     new DefaultDriverData(driver)), OpenFlowSwitchDriver.class);
             ofSwitchDriver.init(new Dpid(dpid), desc, ofv);
diff --git a/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/OpenFlowControllerImpl.java b/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/OpenFlowControllerImpl.java
index b361478..416abd3 100644
--- a/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/OpenFlowControllerImpl.java
+++ b/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/OpenFlowControllerImpl.java
@@ -25,6 +25,7 @@
 import org.apache.felix.scr.annotations.Reference;
 import org.apache.felix.scr.annotations.ReferenceCardinality;
 import org.apache.felix.scr.annotations.Service;
+import org.onosproject.net.driver.DefaultDriverProviderService;
 import org.onosproject.net.driver.DriverService;
 import org.onosproject.openflow.controller.DefaultOpenFlowPacketContext;
 import org.onosproject.openflow.controller.Dpid;
@@ -81,6 +82,10 @@
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected DriverService driverService;
 
+    // References exists merely for sequencing purpose to assure drivers are loaded
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected DefaultDriverProviderService defaultDriverProviderService;
+
     private final ExecutorService executorMsgs =
         Executors.newFixedThreadPool(32, groupedThreads("onos/of", "event-stats-%d"));
 
@@ -507,11 +512,10 @@
             connectedSwitches.remove(dpid);
             OpenFlowSwitch sw = activeMasterSwitches.remove(dpid);
             if (sw == null) {
-                log.warn("sw was null for {}", dpid);
+                log.debug("sw was null for {}", dpid);
                 sw = activeEqualSwitches.remove(dpid);
             }
             for (OpenFlowSwitchListener l : ofSwitchListener) {
-                log.warn("removal for {}", dpid);
                 l.switchRemoved(dpid);
             }
         }
diff --git a/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/RoleManager.java b/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/RoleManager.java
index 2d7e2e7..e7e5ffe 100644
--- a/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/RoleManager.java
+++ b/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/RoleManager.java
@@ -92,7 +92,7 @@
             // ensuring that the only two roles sent to 1.0 switches with
             // Nicira role support, are MASTER and SLAVE
             roleToSend = OFNiciraControllerRole.ROLE_OTHER;
-            log.warn("Sending Nx Role.SLAVE to switch {}.", sw);
+            log.debug("Sending Nx Role.SLAVE to switch {}.", sw);
         }
         int xid = sw.getNextTransactionId();
         OFExperimenter roleRequest = OFFactories.getFactory(OFVersion.OF_10)