3 files changed, 28 insertions, 14 deletions

diff --git a/drivers/infiniband/ulp/ipoib/ipoib.h b/drivers/infiniband/ulp/ipoib/ipoib.h
index b0ffc9abe8c0..05eb41b8ab63 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib.h
+++ b/drivers/infiniband/ulp/ipoib/ipoib.h
@@ -293,6 +293,7 @@ struct ipoib_dev_priv {
 
 	struct delayed_work pkey_poll_task;
 	struct delayed_work mcast_task;
+	struct work_struct carrier_on_task;
 	struct work_struct flush_light;
 	struct work_struct flush_normal;
 	struct work_struct flush_heavy;
@@ -464,6 +465,7 @@ int ipoib_dev_init(struct net_device *dev, struct ib_device *ca, int port);
 void ipoib_dev_cleanup(struct net_device *dev);
 
 void ipoib_mcast_join_task(struct work_struct *work);
+void ipoib_mcast_carrier_on_task(struct work_struct *work);
 void ipoib_mcast_send(struct net_device *dev, void *mgid, struct sk_buff *skb);
 
 void ipoib_mcast_restart_task(struct work_struct *work);
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 7e9e218738fa..e9ca3cb57d52 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -404,7 +404,7 @@ static void path_rec_completion(int status,
 	struct net_device *dev = path->dev;
 	struct ipoib_dev_priv *priv = netdev_priv(dev);
 	struct ipoib_ah *ah = NULL;
-	struct ipoib_ah *old_ah;
+	struct ipoib_ah *old_ah = NULL;
 	struct ipoib_neigh *neigh, *tn;
 	struct sk_buff_head skqueue;
 	struct sk_buff *skb;
@@ -428,12 +428,12 @@ static void path_rec_completion(int status,
 
 	spin_lock_irqsave(&priv->lock, flags);
 
-	old_ah   = path->ah;
-	path->ah = ah;
-
 	if (ah) {
 		path->pathrec = *pathrec;
 
+		old_ah   = path->ah;
+		path->ah = ah;
+
 		ipoib_dbg(priv, "created address handle %p for LID 0x%04x, SL %d\n",
 			  ah, be16_to_cpu(pathrec->dlid), pathrec->sl);
 
@@ -1075,6 +1075,7 @@ static void ipoib_setup(struct net_device *dev)
 
 	INIT_DELAYED_WORK(&priv->pkey_poll_task, ipoib_pkey_poll);
 	INIT_DELAYED_WORK(&priv->mcast_task,   ipoib_mcast_join_task);
+	INIT_WORK(&priv->carrier_on_task, ipoib_mcast_carrier_on_task);
 	INIT_WORK(&priv->flush_light,   ipoib_ib_dev_flush_light);
 	INIT_WORK(&priv->flush_normal,   ipoib_ib_dev_flush_normal);
 	INIT_WORK(&priv->flush_heavy,   ipoib_ib_dev_flush_heavy);
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
index ac33c8f3ea85..aae28620a6e5 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
@@ -366,6 +366,21 @@ static int ipoib_mcast_sendonly_join(struct ipoib_mcast *mcast)
 	return ret;
 }
 
+void ipoib_mcast_carrier_on_task(struct work_struct *work)
+{
+	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
+						   carrier_on_task);
+
+	/*
+	 * Take rtnl_lock to avoid racing with ipoib_stop() and
+	 * turning the carrier back on while a device is being
+	 * removed.
+	 */
+	rtnl_lock();
+	netif_carrier_on(priv->dev);
+	rtnl_unlock();
+}
+
 static int ipoib_mcast_join_complete(int status,
 				     struct ib_sa_multicast *multicast)
 {
@@ -392,16 +407,12 @@ static int ipoib_mcast_join_complete(int status,
 					   &priv->mcast_task, 0);
 		mutex_unlock(&mcast_mutex);
 
-		if (mcast == priv->broadcast) {
-			/*
-			 * Take RTNL lock here to avoid racing with
-			 * ipoib_stop() and turning the carrier back
-			 * on while a device is being removed.
-			 */
-			rtnl_lock();
-			netif_carrier_on(dev);
-			rtnl_unlock();
-		}
+		/*
+		 * Defer carrier on work to ipoib_workqueue to avoid a
+		 * deadlock on rtnl_lock here.
+		 */
+		if (mcast == priv->broadcast)
+			queue_work(ipoib_workqueue, &priv->carrier_on_task);
 
 		return 0;
 	}