Commit a1ff94c2 authored by Vladimir Oltean's avatar Vladimir Oltean Committed by David S. Miller
Browse files

net: dsa: stop updating master MTU from master.c 



At present there are two paths for changing the MTU of the DSA master.

The first is:

dsa_tree_setup
-> dsa_tree_setup_ports
   -> dsa_port_setup
      -> dsa_slave_create
         -> dsa_slave_change_mtu
            -> dev_set_mtu(master)

The second is:

dsa_tree_setup
-> dsa_tree_setup_master
   -> dsa_master_setup
      -> dev_set_mtu(dev)

So the dev_set_mtu() call from dsa_master_setup() has been effectively
superseded by the dsa_slave_change_mtu(slave_dev, ETH_DATA_LEN) that is
done from dsa_slave_create() for each user port. The later function also
updates the master MTU according to the largest user port MTU from the
tree. Therefore, updating the master MTU through a separate code path
isn't needed.

Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e31dbd3b

net/dsa/master.c

+1 −24
Original line number Diff line number Diff line
@@ -330,28 +330,13 @@ static const struct attribute_group dsa_group = { 
	.attrs	= dsa_slave_attrs,

};



static void dsa_master_reset_mtu(struct net_device *dev)

{

	int err;



	rtnl_lock();

	err = dev_set_mtu(dev, ETH_DATA_LEN);

	if (err)

		netdev_dbg(dev,

			   "Unable to reset MTU to exclude DSA overheads\n");

	rtnl_unlock();

}



static struct lock_class_key dsa_master_addr_list_lock_key;



int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)

{

	const struct dsa_device_ops *tag_ops = cpu_dp->tag_ops;

	struct dsa_switch *ds = cpu_dp->ds;

	struct device_link *consumer_link;

	int mtu, ret;



	mtu = ETH_DATA_LEN + dsa_tag_protocol_overhead(tag_ops);

	int ret;



	/* The DSA master must use SET_NETDEV_DEV for this to work. */

	consumer_link = device_link_add(ds->dev, dev->dev.parent,
@@ -361,13 +346,6 @@ int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp) 
			   "Failed to create a device link to DSA switch %s\n",

			   dev_name(ds->dev));



	rtnl_lock();

	ret = dev_set_mtu(dev, mtu);

	rtnl_unlock();

	if (ret)

		netdev_warn(dev, "error %d setting MTU to %d to include DSA overhead\n",

			    ret, mtu);



	/* If we use a tagging format that doesn't have an ethertype

	 * field, make sure that all packets from this point on get

	 * sent to the tag format's receive function.
@@ -405,7 +383,6 @@ void dsa_master_teardown(struct net_device *dev) 
	sysfs_remove_group(&dev->dev.kobj, &dsa_group);

	dsa_netdev_ops_set(dev, NULL);

	dsa_master_ethtool_teardown(dev);

	dsa_master_reset_mtu(dev);

	dsa_master_set_promiscuity(dev, -1);



	dev->dsa_ptr = NULL;