HP lt4120 failing to make single-stack connections on LTE using MM

[Dan Williams]

On Thu, 2018-09-06 at 11:02 +0200, Aleksander Morgado wrote:
> On Thu, Sep 6, 2018 at 10:46 AM, Bjørn Mork <bjorn at mork.no> wrote:
> > Aleksander Morgado <aleksander at aleksander.es> writes:
> > 
> > > Oh wait, this is a Intel based MBIM modem, right? If so, we need
> > > AT-based reset operations. I believe I still have the HPlt4120
> > > around
> > > here, will try to implement that. Tracking it here:
> > > https://gitlab.freedesktop.org/mobile-broadband/ModemManager/issu
> > > es/86
> > 
> > Don't know if we've discussed this before, but based on testing
> > with the
> > EM7345 and looking at the Windows stuff, I believe it supports a
> > vendor
> > MBIM service usable for reset:
> > 
> > UUID_FWUSVC =>  UNKNOWN (0ed374cb-f835-4474-bc11-3b3fd76f5641)
> >     DssPayload: 0x00000000
> >     MaxDssInstances:    0
> >     CidCount:   1
> >     CidList:    1
> >    CID_MODEM_REBOOT   <unknown> (1)
> > 
> > 
> > My notes are a bit sketchy as always, and the modem is stowed away,
> > but
> > I believe that was the only CID of that service and that it only
> > supported SET requests.  With immediate modem reset as a result.
> > 
> 
> Ah, even better, thanks for the pointer :)
> https://gitlab.freedesktop.org/mobile-broadband/libmbim/issues/3

Not sure this does exactly what we want though, as the Telit xN930
documentation for CID_MODEM_REBOOT says:

"This command reboots the device into firmware update mode. After the
command is sent the device shuts down and reboots in firmware update
mode."

Dan