EM7421 failed in NETDEV WATCHDOG: wwan0 (cdc_mbim): transmit queue 0 timed out

[jyijyi]

would you consider to use RMNET (set in AT!USBCOMP) instead of MBIM?

if so, you can see here:

Example on establishing data connection by AT!SCACT via MBPL R20 driver

If anyone is interested in the background - here’s a PoC patch for dhclient I wrote a few years ago: Re: MC 7304 ipv4v6 - raw-ip in qmi/mm/nm