troubleshooting a Quectel EC25-E modem

[Aleksander Morgado]

> When I connect it to my PC (running OpenSUSE Tumbleweed, qmicli is version
> 1.20.0 here) I get a normal output in dmesg
>
> |[50477.827418] usb 2-1.5.2: new high-speed USB device number 12 using
> ehci-pci [50477.945515] usb 2-1.5.2: New USB device found, idVendor=2c7c,
> idProduct=0125 [50477.945523] usb 2-1.5.2: New USB device strings: Mfr=1,
> Product=2, SerialNumber=0 [50477.945527] usb 2-1.5.2: Product: Android
> [50477.945531] usb 2-1.5.2: Manufacturer: Android [50477.946831] option
> 2-1.5.2:1.0: GSM modem (1-port) converter detected [50477.947098] usb
> 2-1.5.2: GSM modem (1-port) converter now attached to ttyUSB0 [50477.947479]
> option 2-1.5.2:1.1: GSM modem (1-port) converter detected [50477.947815] usb
> 2-1.5.2: GSM modem (1-port) converter now attached to ttyUSB1 [50477.948227]
> option 2-1.5.2:1.2: GSM modem (1-port) converter detected [50477.948652] usb
> 2-1.5.2: GSM modem (1-port) converter now attached to ttyUSB2 [50477.949066]
> option 2-1.5.2:1.3: GSM modem (1-port) converter detected [50477.949479] usb
> 2-1.5.2: GSM modem (1-port) converter now attached to ttyUSB3 [50477.950365]
> qmi_wwan 2-1.5.2:1.4: cdc-wdm0: USB WDM device [50477.953115] qmi_wwan
> 2-1.5.2:1.4 wwan0: register 'qmi_wwan' at usb-0000:00:1d.0-1.5.2, WWAN/QMI
> device, 16:9f:df:80:d5:ca [50478.769176] qmi_wwan 2-1.5.2:1.4
> wwp0s29u1u5u2i4: renamed from wwan0|
>
> But it seems I can't communicate with it at all from the PC, any command
> from qmicli fails with the same error
>
> qmicli -d /dev/cdc-wdm0 --nas-get-system-info
> [28 mag 2018, 01:21:55] -Warning ** Error reading from istream: Resource
> temporarily unavailable
>

Is ModemManager running in the system already? You can check that
listing modems with "mmcli -L".
If you want to make sure your qmicli commands don't collide with
whatever MM is doing, append a "-p" to all your qmicli commands, so
that they all go through the qmi-proxy (MM also uses qmi-proxy by
default).

-- 
Aleksander
https://aleksander.es