Modem Manager bring up

[Aleksander Morgado]

Hey,

On Fri, Feb 4, 2022 at 10:07 PM Senthil Kumaresan
<sekumarejobs at gmail.com> wrote:
>
> The ModemManager 1.18.4 is built successfully for my arm platform with all necessary DBUS, libqmi,
> glib packages. I did compile ModemManager --with-udev support. I have a Qualcomm SDX modem module
> connected into my host and it was detected and did see in /sys/bus/pci/xx.
>

You first need to make sure mhi-net and the wwan subsystem are
correctly built in your kernel.
Do you see a /dev/wwan0mbim0 or /dev/wwan0qmi0 port in the system?
Do you see a wwan0 network interface?

> 1) is libudev mandatory for PCIe based devices?
>

It is mandatory if you want to have automatic device detection. If
your system supports udev, you should use udev. The non-udev builds
are for system that rely on other ways to report device
addition/removal events, like e.g. openwrt and its hotplug scripts.

> 2) I have observed that there is no vendor id in the mm-plugin-qcom-soc. c file. So I have added the
> vendor_id field as below.
>
> static const guint16 vendor_ids[] = {
>         0x17cb, /* pci vid */
>         0 };
>

That is not right I'm afraid. The qcom-soc plugin is *exclusively* for
systems running in Qualcomm SoCs, where the "modem" is provided by the
"host" itself.
In your case, you have an ARM host, and an external SDX55 modem
connected via PCIe; the qcom-soc plugin is not for that.

If you're using a generic non-rebranded SDX55, you can rely on the
"generic" plugin giving you support for the modem, forget about the
qcom-soc plugin. And there's no need to add the vid:pid anywhere, just
let it fallback to the generic plugin.

-- 
Aleksander
https://aleksander.es