git.openwrt.org Git - openwrt/staging/xback.git/blob

   1 From a1ff94c2973c43bc1e2677ac63ebb15b1d1ff846 Mon Sep 17 00:00:00 2001
   2 From: Vladimir Oltean <vladimir.oltean@nxp.com>
   3 Date: Thu, 6 Jan 2022 01:11:14 +0200
   4 Subject: [PATCH 3/6] net: dsa: stop updating master MTU from master.c
   5
   6 At present there are two paths for changing the MTU of the DSA master.
   7
   8 The first is:
   9
  10 dsa_tree_setup
  11 -> dsa_tree_setup_ports
  12    -> dsa_port_setup
  13       -> dsa_slave_create
  14          -> dsa_slave_change_mtu
  15             -> dev_set_mtu(master)
  16
  17 The second is:
  18
  19 dsa_tree_setup
  20 -> dsa_tree_setup_master
  21    -> dsa_master_setup
  22       -> dev_set_mtu(dev)
  23
  24 So the dev_set_mtu() call from dsa_master_setup() has been effectively
  25 superseded by the dsa_slave_change_mtu(slave_dev, ETH_DATA_LEN) that is
  26 done from dsa_slave_create() for each user port. The later function also
  27 updates the master MTU according to the largest user port MTU from the
  28 tree. Therefore, updating the master MTU through a separate code path
  29 isn't needed.
  30
  31 Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
  32 Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
  33 Signed-off-by: David S. Miller <davem@davemloft.net>
  34 ---
  35  net/dsa/master.c | 25 +------------------------
  36  1 file changed, 1 insertion(+), 24 deletions(-)
  37
  38 diff --git a/net/dsa/master.c b/net/dsa/master.c
  39 index e8e19857621b..f4efb244f91d 100644
  40 --- a/net/dsa/master.c
  41 +++ b/net/dsa/master.c
  42 @@ -330,28 +330,13 @@ static const struct attribute_group dsa_group = {
  43         .attrs  = dsa_slave_attrs,
  44  };
  45
  46 -static void dsa_master_reset_mtu(struct net_device *dev)
  47 -{
  48 -       int err;
  49 -
  50 -       rtnl_lock();
  51 -       err = dev_set_mtu(dev, ETH_DATA_LEN);
  52 -       if (err)
  53 -               netdev_dbg(dev,
  54 -                          "Unable to reset MTU to exclude DSA overheads\n");
  55 -       rtnl_unlock();
  56 -}
  57 -
  58  static struct lock_class_key dsa_master_addr_list_lock_key;
  59
  60  int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
  61  {
  62 -       const struct dsa_device_ops *tag_ops = cpu_dp->tag_ops;
  63         struct dsa_switch *ds = cpu_dp->ds;
  64         struct device_link *consumer_link;
  65 -       int mtu, ret;
  66 -
  67 -       mtu = ETH_DATA_LEN + dsa_tag_protocol_overhead(tag_ops);
  68 +       int ret;
  69
  70         /* The DSA master must use SET_NETDEV_DEV for this to work. */
  71         consumer_link = device_link_add(ds->dev, dev->dev.parent,
  72 @@ -361,13 +346,6 @@ int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
  73                            "Failed to create a device link to DSA switch %s\n",
  74                            dev_name(ds->dev));
  75
  76 -       rtnl_lock();
  77 -       ret = dev_set_mtu(dev, mtu);
  78 -       rtnl_unlock();
  79 -       if (ret)
  80 -               netdev_warn(dev, "error %d setting MTU to %d to include DSA overhead\n",
  81 -                           ret, mtu);
  82 -
  83         /* If we use a tagging format that doesn't have an ethertype
  84          * field, make sure that all packets from this point on get
  85          * sent to the tag format's receive function.
  86 @@ -405,7 +383,6 @@ void dsa_master_teardown(struct net_device *dev)
  87         sysfs_remove_group(&dev->dev.kobj, &dsa_group);
  88         dsa_netdev_ops_set(dev, NULL);
  89         dsa_master_ethtool_teardown(dev);
  90 -       dsa_master_reset_mtu(dev);
  91         dsa_master_set_promiscuity(dev, -1);
  92
  93         dev->dsa_ptr = NULL;
  94 --
  95 2.34.1
  96