cxgb3: Set vlan_feature on net_device

cxgb3 interface has a bad performance when VLAN is set. On my current
setup, a PowerLinux 7R2, I am able to get around 7 Gbps on a TCP_STREAM
(8 instances, 4k message).
With this patch, I am able to reach 9.5 Gbps.
Signed-off-by: NBreno Leitao <brenohl@br.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb3/cxgb3_main.c

@@ -3173,6 +3173,9 @@ static void __devinit cxgb3_init_iscsi_mac(struct net_device *dev)
 	pi->iscsic.mac_addr[3] |= 0x80;
 }
 
+#define TSO_FLAGS (NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_TSO_ECN)
+#define VLAN_FEAT (NETIF_F_SG | NETIF_F_IP_CSUM | TSO_FLAGS | \
+			NETIF_F_IPV6_CSUM | NETIF_F_HIGHDMA)
 static int __devinit init_one(struct pci_dev *pdev,
 			      const struct pci_device_id *ent)
 {
@@ -3293,6 +3296,7 @@ static int __devinit init_one(struct pci_dev *pdev,
 		netdev->hw_features = NETIF_F_SG | NETIF_F_IP_CSUM |
 			NETIF_F_TSO | NETIF_F_RXCSUM | NETIF_F_HW_VLAN_RX;
 		netdev->features |= netdev->hw_features | NETIF_F_HW_VLAN_TX;
+		netdev->vlan_features |= netdev->features & VLAN_FEAT;
 		if (pci_using_dac)
 			netdev->features |= NETIF_F_HIGHDMA;