Subject: [PATCH 1/2] igb: Allow extra 4 bytes on RX for vlan tags.

From: [email-masked]
Date: Thu, 10 Feb 2011 13:59:08 -0800

From: Ben Greear <[email-masked]>

This allows the NIC to receive 1518 byte (not counting
FCS) packets when MTU is 1500, thus allowing 1500 MTU
VLAN frames to be received.  Please note that no VLANs
were actually configured on the NIC...it was just acting
as pass-through device.

Signed-off-by: Ben Greear <[email-masked]>
---
:100644 100644 58c665b... 30c9cc6... M	drivers/net/igb/igb_main.c
 drivers/net/igb/igb_main.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c
index 58c665b..30c9cc6 100644
--- a/drivers/net/igb/igb_main.c
+++ b/drivers/net/igb/igb_main.c
@@ -2281,7 +2281,8 @@ static int __devinit igb_sw_init(struct igb_adapter *adapter)
 	adapter->rx_itr_setting = IGB_DEFAULT_ITR;
 	adapter->tx_itr_setting = IGB_DEFAULT_ITR;
 
-	adapter->max_frame_size = netdev->mtu + ETH_HLEN + ETH_FCS_LEN;
+	adapter->max_frame_size = (netdev->mtu + ETH_HLEN + ETH_FCS_LEN
+				   + VLAN_HLEN);
 	adapter->min_frame_size = ETH_ZLEN + ETH_FCS_LEN;
 
 	spin_lock_init(&adapter->stats64_lock);
@@ -4303,7 +4304,7 @@ static int igb_change_mtu(struct net_device *netdev, int new_mtu)
 {
 	struct igb_adapter *adapter = netdev_priv(netdev);
 	struct pci_dev *pdev = adapter->pdev;
-	int max_frame = new_mtu + ETH_HLEN + ETH_FCS_LEN;
+	int max_frame = new_mtu + ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN;
 	u32 rx_buffer_len, i;
 
 	if ((new_mtu < 68) || (max_frame > MAX_JUMBO_FRAME_SIZE)) {
-- 
1.7.2.3