I’m debugging an OpenWRT based device that has a EG06 module. By default the module is managed using the QMI port via libqmi+ModemManager, and that works well.
The problem is that there are certain devices, e.g. one with firmware EG06ELAR03A05M4G where the QMI port ends up not being usable any more, even after full module power offs and resets. In this setup, the cdc-wdm port and wwan port associated to the QMI interface are correctly exposed by the kernel, but the QMI cdc-wdm control port remains fully “silent”. It doesn’t reply to any of the QMI commands sent, not even to the QMI CTL service ones.
This looks like the firmware got into a stuck state of some sort. How could I debug this further? Should I try to run a QLog session to gather more info, or is this a known problem for this firmware?