IB/IPoIB: Forward MTU change to driver below

This patch checks if there is a driver below that
needs to be updated on the new MTU and calls it
accordingly.

Signed-off-by: Erez Shitrit <erezsh@mellanox.com>
Reviewed by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 6e86eeee370e86602977bbf3f3949bf2d5ac26ef..3e2b7988ead81ba42f005ab219ca77b88f05873a 100644 (file)
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -233,6 +233,7 @@ static netdev_features_t ipoib_fix_features(struct net_device *dev, netdev_featu
 static int ipoib_change_mtu(struct net_device *dev, int new_mtu)
 {
        struct ipoib_dev_priv *priv = ipoib_priv(dev);
+       int ret = 0;
 
        /* dev->mtu > 2K ==> connected mode */
        if (ipoib_cm_admin_enabled(dev)) {
@@ -256,9 +257,23 @@ static int ipoib_change_mtu(struct net_device *dev, int new_mtu)
                ipoib_dbg(priv, "MTU must be smaller than the underlying "
                                "link layer MTU - 4 (%u)\n", priv->mcast_mtu);
 
-       dev->mtu = min(priv->mcast_mtu, priv->admin_mtu);
+       new_mtu = min(priv->mcast_mtu, priv->admin_mtu);
 
-       return 0;
+       if (priv->rn_ops->ndo_change_mtu) {
+               bool carrier_status = netif_carrier_ok(dev);
+
+               netif_carrier_off(dev);
+
+               /* notify lower level on the real mtu */
+               ret = priv->rn_ops->ndo_change_mtu(dev, new_mtu);
+
+               if (carrier_status)
+                       netif_carrier_on(dev);
+       } else {
+               dev->mtu = new_mtu;
+       }
+
+       return ret;
 }
 
 /* Called with an RCU read lock taken */