ANN: ModemManager 1.18.4 released

Peter Naulls peter at
Mon Nov 29 15:52:51 UTC 2021

On 11/26/21 4:52 AM, Aleksander Morgado wrote:
> Hey hey,
> This is the second bugfix release in the 1.18.x series, built from the mm-1-18 
> branch.


I've been chasing, as I mentioned a while ago, where "sometimes" the modem 
connection will be brought up as PPP, not qmi. This kind of connection fails
in our setup for a bunch of reasons, and is not desirable.

I know that PPP is woven into ModemManager for several reasons, and building
without is some work - I've seen several prior discussions on this topic.

I'm using a custom version of OpenWrt which is approximately the current
release. I've mitigated the problem somewhat by removing the PPP connection
scripts (/lib/netif/ppp*), which helps a little.  I'm using ModemManager
1.18.2 presently, which seems to work pretty well against kernel 4.14.256.
Some versions of the kernel (perhaps due to timing or whatever) seem to
trigger the problem more often, although it's hard to confirm that one
way or another.

The QMI driver I have is highly customized, and may well be the root of the
problem - recent kernels seem to have some validation around USB devices
and whatnot.

In any case, I tested 1.18.4 today, and 100% of the time the connection
now comes up in PPP.  It's not clear from the changes why this might
now happen - perhaps there's extra validation or something.  But I'd
really like to get to the bottom of this - any suggestions in the current
changes that I should look at?

Thanks again.

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