i40e/i40evf: adjust packet size to account for double VLANs

Now that the kernel supports double VLAN tags, we should at least play
nice. Adjust the max packet size to account for two VLAN tags, not just
one.
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

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

@@ -9770,8 +9770,7 @@ static int i40e_config_netdev(struct i40e_vsi *vsi)
 
 	/* MTU range: 68 - 9706 */
 	netdev->min_mtu = ETH_MIN_MTU;
-	netdev->max_mtu = I40E_MAX_RXBUFFER -
-			  (ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN);
+	netdev->max_mtu = I40E_MAX_RXBUFFER - I40E_PACKET_HDR_PAD;
 
 	return 0;
 }

drivers/net/ethernet/intel/i40e/i40e_txrx.h

@@ -130,6 +130,7 @@ enum i40e_dyn_idx_t {
  * i.e. RXBUFFER_512 --> 1216 byte skb (size-2048 slab)
  */
 #define I40E_RX_HDR_SIZE I40E_RXBUFFER_256
+#define I40E_PACKET_HDR_PAD (ETH_HLEN + ETH_FCS_LEN + (VLAN_HLEN * 2))
 #define i40e_rx_desc i40e_32byte_rx_desc
 
 #define I40E_RX_DMA_ATTR \

drivers/net/ethernet/intel/i40evf/i40e_txrx.h

@@ -117,6 +117,7 @@ enum i40e_dyn_idx_t {
  * i.e. RXBUFFER_512 --> 1216 byte skb (size-2048 slab)
  */
 #define I40E_RX_HDR_SIZE I40E_RXBUFFER_256
+#define I40E_PACKET_HDR_PAD (ETH_HLEN + ETH_FCS_LEN + (VLAN_HLEN * 2))
 #define i40e_rx_desc i40e_32byte_rx_desc
 
 #define I40E_RX_DMA_ATTR \

drivers/net/ethernet/intel/i40evf/i40evf_main.c

@@ -2625,7 +2625,7 @@ static void i40evf_init_task(struct work_struct *work)
 
 	/* MTU range: 68 - 9710 */
 	netdev->min_mtu = ETH_MIN_MTU;
-	netdev->max_mtu = I40E_MAX_RXBUFFER - (ETH_HLEN + ETH_FCS_LEN);
+	netdev->max_mtu = I40E_MAX_RXBUFFER - I40E_PACKET_HDR_PAD;
 
 	if (!is_valid_ether_addr(adapter->hw.mac.addr)) {
 		dev_info(&pdev->dev, "Invalid MAC address %pM, using random\n",