Tentative patch-formatted text for patch submission.

mv643xx_eth.txt

From 6005805794dec4f66a06b8aa8379e6e59120944b Mon Sep 17 00:00:00 2001
From: "Tuan T. Pham" <tuan@vt.edu>
Date: Mon, 11 Nov 2013 16:32:26 -0500
Subject: [PATCH] net: mv643xx_eth: add jumbo frame support

On Marvell 510 chip and others, hardware TCP TX checksum is only
supported for mtu up to 1600.  When we set the mtu higher than this, we
need to turn this feature off otherwise we cannot set jumbo frame.

Without this patch, the iperf throughput on Cubox (Marvell 510) is
around 70MB/s inbound and outbound. And, we cannot set the mtu higher
than 1600.

With this patch, the iperf throughput on Cubox is over 100MB/s and we
can set the mtu higher than 1600.

Original author: Rabeeh Khoury

Signed-off-by: Tuan T. Pham <tuan@vt.edu>
---
 drivers/net/ethernet/marvell/mv643xx_eth.c |    7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/ethernet/marvell/mv643xx_eth.c b/drivers/net/ethernet/marvell/mv643xx_eth.c
index 2c210ec..528770b 100644
--- a/drivers/net/ethernet/marvell/mv643xx_eth.c
+++ b/drivers/net/ethernet/marvell/mv643xx_eth.c
@@ -2333,6 +2333,13 @@ static int mv643xx_eth_change_mtu(struct net_device *dev, int new_mtu)
 	dev->mtu = new_mtu;
 	mv643xx_eth_recalc_skb_size(mp);
 	tx_set_rate(mp, 1000000000, 16777216);
+	if (dev->mtu > 1600) {
+		dev->features &= ~NETIF_F_IP_CSUM;
+		dev->vlan_features &= ~NETIF_F_IP_CSUM;
+	} else {
+		dev->features |= NETIF_F_IP_CSUM;
+		dev->vlan_features |= NETIF_F_IP_CSUM;
+	}
 
 	if (!netif_running(dev))
 		return 0;
-- 
1.7.10.4