MC7455 stuck in MBIM-only USB composition

IoT Modules MC/EM Series
4

This is weird. The request you send is fine, as proven by the MC7304 succcess. I do not understand why you get that error with the MC7455.

To be absolutely sure that I didn’t miss anything, I switched my MC7455 to MBIM mode and tried the exact same command. Down to actually copying your requests and writing it directly to /dev/cdc-wdm0, after doing an MBIM open and allocating the same DMS CID.

perl -e 'print pack("C*", map { hex } @ARGV)'  03 00 00 00 3d 00 00 00 08 00 00 00 01 00 00 00    00 00 00 00 d1 a3 0b c2 f9 7a 6e 43 bf 65 c7 e2     4f b0 f0 d3 01 00 00 00 01 00 00 00 0d 00 00 00    01 0c 00 00 02 03 00 01 00 5b 55 00 00 >/dev/cdc-wdm0

And it worked! I got this reply:

03 00 00 80 4f 00 00 00 08 00 00 00 01 00 00 00 00 00 00 00 d1 a3 0b c2 f9 7a 6e 43 bf 65 c7 e2 4f b0 f0 d3 01 00 00 00 00 00 00 00 1f 00 00 00 01 1e 00 80 02 03 02 01 00 5b 55 12 00 02 04 00 00 00 00 00 10 01 00 08 11 04 00 03 06 08 09

The firmware version is the same as yours:

$ mbimcli -d /dev/cdc-wdm0 --query-device-caps
[/dev/cdc-wdm0] Device capabilities retrieved:
              Device type: 'remote'
           Cellular class: 'gsm'
              Voice class: 'no-voice'
                Sim class: 'removable'
               Data class: 'umts, hsdpa, hsupa, lte'
                 SMS caps: 'pdu-receive, pdu-send'
                Ctrl caps: 'reg-manual'
             Max sessions: '8'
        Custom data class: 'unknown'
                Device ID: '35907206000xxxx'
            Firmware info: 'SWI9X30C_02.08.02.00'
            Hardware info: 'MC7455'

I have no idea what is going on here, which makes it even more risky to play with. But I’ll send you an .nvu file with instructions in private so you can consider trying that trick.