[NET]: TSO requires SG, enforce this at device registry.

Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/dev.c

@@ -2871,6 +2871,14 @@ int register_netdevice(struct net_device *dev)
 		dev->features &= ~NETIF_F_SG;
 	}
 
+	/* TSO requires that SG is present as well. */
+	if ((dev->features & NETIF_F_TSO) &&
+	    !(dev->features & NETIF_F_SG)) {
+		printk("%s: Dropping NETIF_F_TSO since no SG feature.\n",
+		       dev->name);
+		dev->features &= ~NETIF_F_TSO;
+	}
+
 	/*
 	 *	nil rebuild_header routine,
 	 *	that should be never called and used as just bug trap.