i40e: Clarify steps in MAC/VLAN filters initialization routine

This patch clarifies the reason for removal of automatically
firmware-generated filter and explicit addition of filter which
accepts frames with any VLAN id.

Change-ID: Iabf180b6d61c4d8a36d3bcf8457c377a6f2aca0e
Signed-off-by: NFilip Sadowski <filip.sadowski@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e_main.c

@@ -9461,10 +9461,10 @@ static int i40e_config_netdev(struct i40e_vsi *vsi)
 	if (vsi->type == I40E_VSI_MAIN) {
 		SET_NETDEV_DEV(netdev, &pf->pdev->dev);
 		ether_addr_copy(mac_addr, hw->mac.perm_addr);
-		/* The following steps are necessary to prevent reception
-		 * of tagged packets - some older NVM configurations load a
-		 * default a MAC-VLAN filter that accepts any tagged packet
-		 * which must be replaced by a normal filter.
+		/* The following steps are necessary to properly keep track of
+		 * MAC-VLAN filters loaded into firmware - first we remove
+		 * filter that is automatically generated by firmware and then
+		 * add new filter both to the driver hash table and firmware.
 		 */
 		i40e_rm_default_mac_filter(vsi, mac_addr);
 		spin_lock_bh(&vsi->mac_filter_hash_lock);