Hello,

I am trying to use a Quectel EC20 card (cellular/LTE). I installed wwan and uqmi and it works for the most part.

However, when proto/qmi.sh calls the ubus "add_dynamic" method to create my_if_4 with ifname="@my_if", it returns with an error, which is ignored in the qmi.sh script.

I suspected this error could be a hiding a deeper problem.

I tracked that down to netifd: ubus.c, netifd_add_dynamic() where this test fails:

        dev = iface->main_dev.dev;
        if (!dev || !dev->default_config) {
                return UBUS_STATUS_UNKNOWN_ERROR;
        }

"dev" exists but default_config is false.

I tried with and without an "option ifname wwan0" in /etc/config/network, with the same result.

But after some research I still do not understand the significance and need for this flag, and why it is important for add_dynamic, and what I do wrong so that is stays unset.

Any hint ?