Function netdev_lower_unregister

drivers/net/netdev_upperhalf.c:1468–1519

 ****************************************************************************/

int netdev_lower_unregister(FAR struct netdev_lowerhalf_s *dev)
{
  FAR struct netdev_upperhalf_s *upper;
  int cpu = 1;
  int ret;

  if (dev == NULL || dev->netdev.d_private == NULL)
    {
      nerr("ERROR: Invalid lower half device\n");
      return -EINVAL;
    }

  upper = (FAR struct netdev_upperhalf_s *)dev->netdev.d_private;

#ifdef CONFIG_NET_VLAN
  netdev_upper_vlan_foreach(upper, vlan_unregister);
#endif

  ret = netdev_unregister(&dev->netdev);
  if (ret < 0)
    {
      return ret;
    }

  switch (dev->rxtype)
    {
      case NETDEV_RX_THREAD_RSS:
        cpu = CONFIG_SMP_NCPUS;
      case NETDEV_RX_THREAD:

        /* Stop the dedicated thread for network operations in thread mode */

        netdev_upper_exit_thread(upper);
        while (--cpu >= 0)
          {
            FAR struct netdev_thread_s *t = &upper->thread[cpu];

            nxsem_destroy(&t->sem);
            nxsem_destroy(&t->sem_exit);
          }
        break;
    }

#if CONFIG_IOB_NCHAINS > 0
  iob_free_queue(&upper->txq);
#endif

  kmm_free(upper);
  dev->netdev.d_private = NULL;

  return OK;
}

/****************************************************************************
 * Name: netdev_lower_carrier_on