1 files changed, 27 insertions, 0 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 0913a08a87d..c36a17aafcf 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4901,6 +4901,33 @@ unsigned long netdev_fix_features(unsigned long features, const char *name)
 EXPORT_SYMBOL(netdev_fix_features);
 
 /**
+ *      netif_stacked_transfer_operstate -      transfer operstate
+ *      @rootdev: the root or lower level device to transfer state from
+ *      @dev: the device to transfer operstate to
+ *
+ *      Transfer operational state from root to device. This is normally
+ *      called when a stacking relationship exists between the root
+ *      device and the device(a leaf device).
+ */
+void netif_stacked_transfer_operstate(const struct net_device *rootdev,
+                                        struct net_device *dev)
+{
+        if (rootdev->operstate == IF_OPER_DORMANT)
+                netif_dormant_on(dev);
+        else
+                netif_dormant_off(dev);
+
+        if (netif_carrier_ok(rootdev)) {
+                if (!netif_carrier_ok(dev))
+                        netif_carrier_on(dev);
+        } else {
+                if (netif_carrier_ok(dev))
+                        netif_carrier_off(dev);
+        }
+}
+EXPORT_SYMBOL(netif_stacked_transfer_operstate);
+
+/**
  *      register_netdevice      - register a network device
  *      @dev: device to register
  *