Random MM and/or qmi-proxy hang?

[Bowden, Brendan]

> -----Original Message-----
> From: Aleksander Morgado <aleksander at aleksander.es>
> Sent: Wednesday, March 13, 2019 6:36 AM
> To: Bowden, Brendan <bbowden at presidio.com>
> Cc: ModemManager (development) <modemmanager-
> devel at lists.freedesktop.org>
> Subject: Re: Random MM and/or qmi-proxy hang?
>
> EXTERNAL EMAIL
>
>
>
> Hey,
>
> >
> > This is RHEL7 so I’m using the 1.6 branch of MM and 1.18.0 libqmi; for MM I
> tried building our own 1.16.4 when we suspected MM being the core issue,
> with no change in behavior.
> >

Sorry there were some typos there. Versions tested are 1.6.10 (as delivered by RHEL) and 1.16.14 (custom build) with libqmi 1.18.0. I'll look into going up to MM 1.10 and libqmi 1.22 without bringing up a lot of other system dependencies.

>
> Hard to say what the issue is, but you're really using somewhat old versions.
> Any chance you can upgrade them to MM 1.10.0 and libqmi 1.22.2? They
> should be totally compatible.
>
> >
> > Any thoughts? Wanted to see about putting qmi-proxy in debug mode but
> I’m not sure how to do that when it’s already running (spawned by MM). Out
> of ~200 units I’ve got MM debug logging enabled on, 3-4 would get into this
> state after 24 hours, so reproducibility is a problem; haven’t found a way to
> trigger this condition on cue yet. As background info, each unit (3500 out
> there) has two Sierra modems, could be any combination of MC7700,
> MC7750, MC7354 talking to AT&T or Verizon, both LTE and 3G.
>
> You can run the qmi-proxy with verbose info by manually starting it BEFORE
> MM is started.
> E.g.
> $ sudo systemctl stop ModemManager
> $ sudo /usr/libexect/qmi-proxy --no-exit --verbose > /tmp/qmi-proxy-
> verbose.log 2>&1 & $ sudo systemctl start ModemManager

There's a concern that if we explicitly stop ModemManager we lose connectivity to these devices until they get power cycled; cell modems are the only way they have to get back to us. Restart is usually OK because it's an all-in-one action. I can try and tee up a system cron job to 'start' MM if it's missing in action (actually that wouldn't be a bad idea in any event...) but it's not there yet.

There's usually a pretty good delay before MM notices qmi-proxy is gone. If I killed MM's spawn of qmi-proxy and then `systemctl restart`ed  ModemManager would the new instance of qmi-proxy get left alone?

>
> --
> Aleksander
> https://aleksander.es


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