could not grab port cdc-wdm0: Cannot add port 'usbmisc/cdc-wdm0', unhandled port

[Juan A. Rubio]

On Sun, Aug 29, 2021 at 3:31 PM Aleksander Morgado
<aleksander at aleksander.es> wrote:
>
> Hey Juan
>
> > I have a system with MM 1.16.4 (NM 1.20.4) and I'm facing some
> > problems with my SIMCOM SIM7600G-H
> >
> > In some systems, I get a successful activation of the cdc-wdm0 device
> > and the wwan0 interface comes up and in some other systems, cdc-wdm0
> > fails to be grabbed/activated and the wwan0 stays down.
> >
> > I'm attaching the success and failure logs.
> >
> > Any clues on where the issue might lie, or where to look for more
> > info, would be really appreciated.
> >
>
> The MM version you're using has a 25s timeout when checking for the
> QMI support, which may not be enough for newer devices, which take a
> looong time to respond in the QMI port.
>
> You may just need this patch
> https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/commit/b7f0f2ca7c6e61fcf08786909ba0992d0de36ce6
> which was released with MM 1.16.6.
>
> --
> Aleksander
> https://aleksander.es

Thanks Aleksander,

Actually, I moved to MM 1.16.10 and I have not seen that issue since then.

BR,
Juan