Sierra MC7354: Drowning in "bearer verbose call end reason (6,36): [3gpp] regular-deactivation"

[Aleksander Morgado]

Hey,

>
> I am using the Sierra MC7354 modem, and we are getting unusual
> disconnects on AT&T in the US. Vodafone is fine on the same modems,
> and this only seems to happen on 4G. AT&T 3G  seems to work.
>
> We start out connected, but  after a bit of time we hit
> "gsm-wcdma-regular-deactivation/[3gpp] regular-deactivation", and then
> we're spamming the log file with those messages (up to 240 lines/sec).
> Logs below.
> Similar to this post, but seems mostly unrelated.
> https://lists.freedesktop.org/archives/modemmanager-devel/2017-February/003988.html
> We opening/closing PDP connections during this period, but there is no
> connectivity.
>
> Questions:
> 1) Any ideas what is happening?

Nope

> 2) should I be calling ifdown when I hit 'state changed (connected ->
> registered)' ?
>

Are you using NetworkManager as well as ModemManager? Or how do you
setup the network interface?

> We have been in touch with both Sierra and AT&T, but they say that
> libQMI is unsupported. so there is not much help there.
>

Oh well. This is, I would say, NOT related to libqmi in any way. If
they told you this, you should be able to recreate a small test using
Sierra's SDK and see if/how it is reproduced. This is probably your
best shot I'd say, given the type of problem.

> Setup
> Sierra MC7354 modem
> ModemManager 1.6.2
> libQmi 1.16.0
> Arm linux - kernel 3.14
>
> I'm using buildroot, so upgrading libQmi  (to 1.18.0 or 1.20.0) and
> ModemManager (to 1.6.8 or 1.8.0) would be doable. Are there any
> additional benefits in the newer versions regarding this issue?

Well, those versions are extremely old. Please upgrade to the newest
ones and retry, to avoid any possible issue that may already have been
fixed. Those upgrades should be 100% compatible.

-- 
Aleksander
https://aleksander.es