i40e: Retain MAC filters when changing port VLAN

We were already taking care to retain the MAC filter list when deleting a
port VLAN.  Take some additional care to retain the MAC filter list when
changing a port VLAN.

Change-ID: Iacf9599ea24ecb4dca8e419aacaf4b58ca361a9c
Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Signed-off-by: Catherine Sullivan <catherine.sullivan@intel.com>
Tested-by: Sibai Li <sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c

@@ -2128,11 +2128,15 @@ int i40e_ndo_set_vf_port_vlan(struct net_device *netdev,
 
 	/* Check for condition where there was already a port VLAN ID
 	 * filter set and now it is being deleted by setting it to zero.
+	 * Additionally check for the condition where there was a port
+	 * VLAN but now there is a new and different port VLAN being set.
 	 * Before deleting all the old VLAN filters we must add new ones
 	 * with -1 (I40E_VLAN_ANY) or otherwise we're left with all our
 	 * MAC addresses deleted.
 	 */
-	if (!(vlan_id || qos) && vsi->info.pvid)
+	if ((!(vlan_id || qos) ||
+	    (vlan_id | qos) != le16_to_cpu(vsi->info.pvid)) &&
+	    vsi->info.pvid)
 		ret = i40e_vsi_add_vlan(vsi, I40E_VLAN_ANY);
 
 	if (vsi->info.pvid) {