Basic (Idiotic) questions about ModemManager / mmcli / libqmi / modems / life

[Ajay Garg]

Thanks Thomas.


On Sat, Aug 13, 2016 at 10:11 PM,  <tschaefer at t-online.de> wrote:
> Am 13.08.2016 17:28 schrieb Ajay Garg <ajaygargnsit at gmail.com>:
>>
>> Thanks Thomas.
>>
>>
>> Question 2 :
>> =========
>>
>> Let's take a modem working in QMI-mode.
>>
>> With the "qcserial" and "qmi_wwan" drivers installed, and NO OTHER
>> VENDOR-SPECIFIC drivers (sierra/zte/huawei/any-other) required or
>> installed, the modem (after it is inserted in the USB-slot), will have
>> the following two created ::
>>
>>         * /dev/cdc-... device-identifier
>>         * a wwan network-interface (visible via "ifconfig" command)
>>
>> Above two will be created, irrespective of whether or not
>> ModemManager/mmcli is compiled/running with
>> QMI_DEVICE_OPEN_FLAGS_PROXY set or not.
>>
>> Is my understanding correct?
>>
>
> The creation of the device files is made by the kernel/udev. Sometimes
> "option" is also loaded, so you have some additional serial ports.

Question-3
============

Ok, so does this mean that none/one of qcserial/qmi_wwan are required?
Or both are required to have the wwan-network-interface working properly?

In other words, if I understand correctly,

      * /dev/cdc-... would be created, but not by qcserial/qmi_wwan,
but by udev/kernel.
      * wwan network-interface will be created by one or more of
qcserial/qmi_wwan
      * qcserial/qmi_wwan are definitely required for function of
wwan-interface.


Are my comprehensions correct till this point?

>
> Modemmanager uses these device files.
>
> The qmi-proxy is used for concurrent qmi-accesses e.g. by modemmanager
> and qmicli.
>
> https://sigquit.wordpress.com/2013/09/13/sharing-a-qmi-port-between-processes/

Yes Thomas, I have already gone through this link, questions on it
would follow some questions later.
First please allow me (and other newbies too) to get a hang of
minimal-configuration required to get QMI-modems working :)

>
> Ifconfig is obsoleted by ip. Please use ip a or ip l instead.
>
> Thomas



-- 
Regards,
Ajay