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

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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superseded by the dsa_slave_change_mtu(slave_dev, ETH_DATA_LEN) that is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: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Vladimir Oltean 2022-01-06 01:11:14 +02:00 committed by David S. Miller
parent e31dbd3b6a
commit a1ff94c297
1 changed files with 1 additions and 24 deletions
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25
net/dsa/master.c
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@ -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;