Re: [PATCH v2 4/6] net: ocelot: add support for ndo_change_mtu
From: Vladimir Oltean <vladimir.oltean@nxp.com>
Date: 2021-11-03 12:41:01
Also in:
linux-devicetree, lkml
On Wed, Nov 03, 2021 at 10:19:41AM +0100, Clément Léger wrote:
quoted hunk ↗ jump to hunk
This commit adds support for changing MTU for the ocelot register based interface. For ocelot, JUMBO frame size can be set up to 25000 bytes but has been set to 9000 which is a saner value and allow for maximum gain of performances. Frames larger than 9000 bytes do not yield a noticeable improvement. Signed-off-by: Clément Léger <clement.leger@bootlin.com> --- drivers/net/ethernet/mscc/ocelot.h | 2 ++ drivers/net/ethernet/mscc/ocelot_net.c | 14 ++++++++++++++ 2 files changed, 16 insertions(+)diff --git a/drivers/net/ethernet/mscc/ocelot.h b/drivers/net/ethernet/mscc/ocelot.h index e43da09b8f91..ba0dec7dd64f 100644 --- a/drivers/net/ethernet/mscc/ocelot.h +++ b/drivers/net/ethernet/mscc/ocelot.h@@ -32,6 +32,8 @@ #define OCELOT_PTP_QUEUE_SZ 128 +#define OCELOT_JUMBO_MTU 9000 + struct ocelot_port_tc { bool block_shared; unsigned long offload_cnt;diff --git a/drivers/net/ethernet/mscc/ocelot_net.c b/drivers/net/ethernet/mscc/ocelot_net.c index d76def435b23..5916492fd6d0 100644 --- a/drivers/net/ethernet/mscc/ocelot_net.c +++ b/drivers/net/ethernet/mscc/ocelot_net.c@@ -482,6 +482,18 @@ static netdev_tx_t ocelot_port_xmit(struct sk_buff *skb, struct net_device *dev) return NETDEV_TX_OK; } +static int ocelot_change_mtu(struct net_device *dev, int new_mtu) +{ + struct ocelot_port_private *priv = netdev_priv(dev); + struct ocelot_port *ocelot_port = &priv->port; + struct ocelot *ocelot = ocelot_port->ocelot; + + ocelot_port_set_maxlen(ocelot, priv->chip_port, new_mtu); + WRITE_ONCE(dev->mtu, new_mtu);
The WRITE_ONCE seems absolutely gratuitous to me.
quoted hunk ↗ jump to hunk
+ + return 0; +} + enum ocelot_action_type { OCELOT_MACT_LEARN, OCELOT_MACT_FORGET,@@ -768,6 +780,7 @@ static const struct net_device_ops ocelot_port_netdev_ops = { .ndo_open = ocelot_port_open, .ndo_stop = ocelot_port_stop, .ndo_start_xmit = ocelot_port_xmit, + .ndo_change_mtu = ocelot_change_mtu, .ndo_set_rx_mode = ocelot_set_rx_mode, .ndo_set_mac_address = ocelot_port_set_mac_address, .ndo_get_stats64 = ocelot_get_stats64,@@ -1699,6 +1712,7 @@ int ocelot_probe_port(struct ocelot *ocelot, int port, struct regmap *target, dev->netdev_ops = &ocelot_port_netdev_ops; dev->ethtool_ops = &ocelot_ethtool_ops; + dev->max_mtu = OCELOT_JUMBO_MTU; dev->hw_features |= NETIF_F_HW_VLAN_CTAG_FILTER | NETIF_F_RXFCS | NETIF_F_HW_TC;-- 2.33.0