EM9291 can't read cdc-wdm0 in Linunx device

IoT Modules MC/EM Series
1

I would like to inquire about the issue with my Linux Ubuntu device not being able to read the port for the EM9291. Below is device information.

  -----------------------------
  General  |              path: /org/freedesktop/ModemManager1/Modem/0
           |         device id: c2c2bc9cc55688720465e4f10591e59e925a12db
  -----------------------------
  Hardware |      manufacturer: Sierra Wireless, Incorporated
           |             model: EM9291
           | firmware revision: SWIX65C_02.13.08.00 505383 jenkins 2023/09/20 16:15:21
           |         supported: gsm-umts
           |           current: gsm-umts
           |      equipment id: 358186652152286
  -----------------------------
  System   |            device: /sys/devices/platform/0.soc/878010000000.pci/pci0001:00/0001:00:0c.0/usb2/2-1
           |           drivers: qcserial
           |            plugin: generic
           |      primary port: ttyUSB0
           |             ports: ttyUSB0 (at), ttyUSB1 (ignored)
  -----------------------------
  Status   |             state: failed
           |     failed reason: sim-missing
           |       power state: on
  -----------------------------
  Modes    |         supported: allowed: any; preferred: none
           |           current: allowed: any; preferred: none
  -----------------------------
  IP       |         supported: ipv4, ipv6, ipv4v6

Bus 004 Device 002: ID 05e3:0620 Genesys Logic, Inc. USB3.2 Hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 002: ID 05e3:0610 Genesys Logic, Inc. Hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 002: ID 1199:90e3 Sierra Wireless, Inc. Sierra Wireless EM9291
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

I want to connect my device to the internet, but it seems that I should have the cdc-wdm0 and wwan0 port. However, why can I only read ttyUSB0?

2

Is the /dev/ttyUSB0 port for AT command?
If yes, you should check

At!entercnd=“A710”
At!usbcomp?

3

Here

AT!ENTERCND="A710"

OK

at!usbcomp?

Config Index: 1
Config Type:  4 (MBIM V2)
Interface bitmask: 00001009 (diag,modem,mbim)

OK
4

probably your linux does not have the MBIM driver installed

I remember it should work for Ubuntu 18 or Ubuntu 20

5

Yes, I am using Ubuntu 22.04, but I have already insmod the MBIM driver.

root@localhost:~# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 22.04.4 LTS
Release:        22.04
Codename:       jammy

root@localhost:~# lsmod
Module                  Size  Used by
sierra                262144  0
qcaux                 262144  0
qmi_wwan              327680  0
r8153_ecm             262144  0
cdc_ncm               327680  0
qcserial              262144  0
cdc_wdm               327680  1 qmi_wwan
cdc_ether             327680  2 r8153_ecm,cdc_ncm
usb_wwan              327680  1 qcserial
usbserial             327680  4 qcaux,qcserial,sierra,usb_wwan
6

it should be like this:


owner@ubuntu:~$ ls /dev/ttyUSB*
/dev/ttyUSB0  /dev/ttyUSB1
owner@ubuntu:~$ lsmod | grep mbim
cdc_mbim               16384  0
cdc_wdm                20480  1 cdc_mbim
cdc_ncm                36864  1 cdc_mbim
usbnet                 45056  2 cdc_mbim,cdc_ncm
owner@ubuntu:~$ lsb_release -a
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu Bionic Beaver (development branch)
Release:	18.04
Codename:	bionic
7

Looks like a problem, I don’t have any information about MBIM.

root@localhost:~# ls /dev/ttyUSB*
/dev/ttyUSB0  /dev/ttyUSB1
root@localhost:~# lsmod | grep mbim
root@localhost:~#

So is it a problem with the MBIM driver?

8

i am not sure, you can check other ubuntu version like ubuntu 18 or ubuntu 20.

9

Thank you, I updated libmbim-utils and network-manager to the latest version,
and insmod cdc_mbim.ko, the interface is back.

root@localhost:~# mmcli -m 0
  -----------------------------------
  General   |                   path: /org/freedesktop/ModemManager1/Modem/0
            |              device id: 6cb451ed08b6f02a8bb81cf3ea3ccb85d2ce5adc
  -----------------------------------
  Hardware  |           manufacturer: Sierra Wireless, Incorporated
            |                  model: Sierra Wireless EM9291
            |         carrier config: default
            |           h/w revision: EM9291
            |              supported: gsm-umts, lte, 5gnr
            |                current: gsm-umts, lte, 5gnr
            |           equipment id: 358186652152252
  -----------------------------------
  System    |                 device: /sys/devices/platform/0.soc/878010000000.pci/pci0001:00/0001:00:0c.0/usb2/2-1
            |                drivers: qcserial, cdc_mbim
            |                 plugin: sierra
            |           primary port: cdc-wdm0
            |                  ports: cdc-wdm0 (mbim), ttyUSB0 (at), wwan0 (net)
  -----------------------------------
  Numbers   |                    own: +886955213667
  -----------------------------------
  Status    |                   lock: sim-pin2
            |         unlock retries: sim-pin2 (3)
            |                  state: registered
            |            power state: on
            |            access tech: lte, 5gnr
            |         signal quality: 54% (recent)
  -----------------------------------