[PATCH 4.0 26/55] net: mvneta: disable IP checksum with jumbo frames for Armada 370

Greg Kroah-Hartman
2015-07-08T08:12:45Z

From: Simon Guinot <simon.guinot@sequanux.org>

[ Upstream commit b65657fc240ae6c1d2a1e62db9a0e61ac9631d7a ]

The Ethernet controller found in the Armada 370, 380 and 385 SoCs don't
support TCP/IP checksumming with frame sizes larger than 1600 bytes.

This patch fixes the issue by disabling the features NETIF_F_IP_CSUM and
NETIF_F_TSO for the Armada 370 and compatibles SoCs when the MTU is set
to a value greater than 1600 bytes.

Signed-off-by: Simon Guinot <simon.guinot@sequanux.org>
Fixes: c5aff18204da ("net: mvneta: driver for Marvell Armada 370/XP network unit")
Cc: <stable@vger.kernel.org> # v3.8+
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/marvell/mvneta.c | 26 +++++++++++++++++++++++++-
1 file changed, 25 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -304,6 +304,7 @@ struct mvneta_port {
unsigned int link;
unsigned int duplex;
unsigned int speed;
+ unsigned int tx_csum_limit;
};

/* The mvneta_tx_desc and mvneta_rx_desc structures describe the
@@ -2441,8 +2442,10 @@ static int mvneta_change_mtu(struct net_

dev->mtu = mtu;

- if (!netif_running(dev))
+ if (!netif_running(dev)) {
+ netdev_update_features(dev);
return 0;
+ }

/* The interface is running, so we have to force a
* reallocation of the queues
@@ -2471,9 +2474,26 @@ static int mvneta_change_mtu(struct net_
mvneta_start_dev(pp);
mvneta_port_up(pp);

+ netdev_update_features(dev);
+
return 0;
}

+static netdev_features_t mvneta_fix_features(struct net_device *dev,
+ netdev_features_t features)
+{
+ struct mvneta_port *pp = netdev_priv(dev);
+
+ if (pp->tx_csum_limit && dev->mtu > pp->tx_csum_limit) {
+ features &= ~(NETIF_F_IP_CSUM | NETIF_F_TSO);
+ netdev_info(dev,
+ "Disable IP checksum for MTU greater than %dB\n",
+ pp->tx_csum_limit);
+ }
+
+ return features;
+}
+
/* Get mac address */
static void mvneta_get_mac_addr(struct mvneta_port *pp, unsigned char *addr)
{
@@ -2785,6 +2805,7 @@ static const struct net_device_ops mvnet
.ndo_set_rx_mode = mvneta_set_rx_mode,
.ndo_set_mac_address = mvneta_set_mac_addr,
.ndo_change_mtu = mvneta_change_mtu,
+ .ndo_fix_features = mvneta_fix_features,
.ndo_get_stats64 = mvneta_get_stats64,
.ndo_do_ioctl = mvneta_ioctl,
};
@@ -3023,6 +3044,9 @@ static int mvneta_probe(struct platform_
}
}

+ if (of_device_is_compatible(dn, "marvell,armada-370-neta"))
+ pp->tx_csum_limit = 1600;
+
pp->tx_ring_size = MVNETA_MAX_TXD;
pp->rx_ring_size = MVNETA_MAX_RXD;