be2net: don't flip hw_features when VXLANs are added/deleted

the be2net implementation of .ndo_tunnel_{add,del}() changes the value of
NETIF_F_GSO_UDP_TUNNEL bit in 'features' and 'hw_features', but it forgets
to call netdev_features_change(). Moreover, ethtool setting for that bit
can potentially be reverted after a tunnel is added or removed.

GSO already does software segmentation when 'hw_enc_features' is 0, even
if VXLAN offload is turned on. In addition, commit 096de2f ("benet:
stricter vxlan offloading check in be_features_check") avoids hardware
segmentation of non-VXLAN tunneled packets, or VXLAN packets having wrong
destination port. So, it's safe to avoid flipping the above feature on
addition/deletion of VXLAN tunnels.

Fixes: 630f4b7 ("be2net: Export tunnel offloads only when a VxLAN tunnel is created")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/emulex/benet/be_main.c

@@ -4002,8 +4002,6 @@ static int be_enable_vxlan_offloads(struct be_adapter *adapter)
 	netdev->hw_enc_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
 				   NETIF_F_TSO | NETIF_F_TSO6 |
 				   NETIF_F_GSO_UDP_TUNNEL;
-	netdev->hw_features |= NETIF_F_GSO_UDP_TUNNEL;
-	netdev->features |= NETIF_F_GSO_UDP_TUNNEL;
 
 	dev_info(dev, "Enabled VxLAN offloads for UDP port %d\n",
 		 be16_to_cpu(port));
@@ -4025,8 +4023,6 @@ static void be_disable_vxlan_offloads(struct be_adapter *adapter)
 	adapter->vxlan_port = 0;
 
 	netdev->hw_enc_features = 0;
-	netdev->hw_features &= ~(NETIF_F_GSO_UDP_TUNNEL);
-	netdev->features &= ~(NETIF_F_GSO_UDP_TUNNEL);
 }
 
 static void be_calculate_vf_res(struct be_adapter *adapter, u16 num_vfs,
@@ -5320,6 +5316,7 @@ static void be_netdev_init(struct net_device *netdev)
 	struct be_adapter *adapter = netdev_priv(netdev);
 
 	netdev->hw_features |= NETIF_F_SG | NETIF_F_TSO | NETIF_F_TSO6 |
+		NETIF_F_GSO_UDP_TUNNEL |
 		NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM | NETIF_F_RXCSUM |
 		NETIF_F_HW_VLAN_CTAG_TX;
 	if ((be_if_cap_flags(adapter) & BE_IF_FLAGS_RSS))