Function netdev_upper_ifup

drivers/net/netdev_upperhalf.c:1208–1257

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

static int netdev_upper_ifup(FAR struct net_driver_s *dev)
{
  FAR struct netdev_upperhalf_s *upper = dev->d_private;
  int cpu = 1;

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

        /* Try to bring up a dedicated thread for work. */

        while (--cpu >= 0)
          {
            FAR struct netdev_thread_s *t = &upper->thread[cpu];
            FAR char *argv[3];
            char      arg1[32];
            char      arg2[32];
            char      name[32];

            snprintf(arg1, sizeof(arg1), "%p", upper);
            argv[0] = arg1;

            snprintf(arg2, sizeof(arg2), "%d", cpu);
            argv[1] = arg2;
            argv[2] = NULL;

            snprintf(name, sizeof(name), NETDEV_THREAD_NAME_FMT,
                     dev->d_ifname);

            t->tid = kthread_create(name, upper->lower->priority,
                                    CONFIG_DEFAULT_TASK_STACKSIZE,
                                    netdev_upper_loop, argv);
            if (t->tid < 0)
              {
                netdev_upper_exit_thread(upper);
                return t->tid;
              }
          }
        break;
    }

  if (upper->lower->ops->ifup)
    {
      return upper->lower->ops->ifup(upper->lower);
    }

  return -ENOSYS;
}

static int netdev_upper_ifdown(FAR struct net_driver_s *dev)
{