e100: make sure vlan support isn't advertised on old adapters

e100 parts don't support vlan offload but they generally do
allow use of vlans in higher software layers via the 8021q module.
That said, there are a couple of really old revisions of e100
hardware that don't even allow the longer frame sizes
required for vlan use with standard MTU.

Use the VLAN_CHALLENGED flag to prevent vlan binding to these
devices.
Reported-by: NMichael Tokarev <mjt@tls.msk.ru>
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
CC: Michael Tokarev <mjt@tls.msk.ru>
CC: David Lamparter <equinox@diac24.net>
Tested-by: NAaron Brown <aaron.f.brown@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/e100.c

@@ -2810,6 +2810,10 @@ static int __devinit e100_probe(struct pci_dev *pdev,
 
 	e100_get_defaults(nic);
 
+	/* D100 MAC doesn't allow rx of vlan packets with normal MTU */
+	if (nic->mac < mac_82558_D101_A4)
+		netdev->features |= NETIF_F_VLAN_CHALLENGED;
+
 	/* locks must be initialized before calling hw_reset */
 	spin_lock_init(&nic->cb_lock);
 	spin_lock_init(&nic->cmd_lock);