Consultation about QMI CID Leaks

IOEE Jimmy Li (EXT) at
Thu Dec 23 09:58:21 UTC 2021

Dear Aleksander,

Thanks for your kind reply.
As you have mentioned, the issue we met has been fixed in commit
16383670dcb471d6a5b802a9cca1e2a24eb86de5, but we failed to find this commit in your gitlab.
Can you please give us a link about this?

Also, we have tested thousands times with Modem Manager(1.18.2) and libqmi(1.31.2). When we repeated the
Syetemctl restart Modem Manager service, there were still CID leaks. And from the hardware signal analysis of modem,
when restarting Modem Manager, the modem of Quectel did not receive all signal to release, which led to CID leaks.
The modem failed to reinitialize and stopped to offer service.

And under same hardware and software conditions, we have tried to modify value of killmode into process on MM and to
reset MM while not reset qmi-proxy. It seems that there is no abnormality of CID. The QMI clients were implicitly tracked by
qmi-proxy and the CID was used repeatedly.

So here is our question. When the service of qmi-proxy stopped, it seems that it's necessary to release the QMI clients which
are in charge of qmi-proxy.

Can you help to explain the root cause of this issue?

Looking forward to your reply. Thanks!

Merry Christmas!

IOEE Jimmy Li | Specialist, Next Generation Cube Program at

-----Original Message-----
From: Aleksander Morgado <aleksander at>
Sent: Monday, December 20, 2021 10:51 PM
To: IOEE Jimmy Li (EXT) < at>
Cc: libqmi-devel at; ModemManager-devel at; Wang Qian (IOT) <wangqian at>
Subject: Re: Consultation about QMI CID Leaks


> I have met some issues about QMI CID leaks when using Quectel's modem
> with modem manager, and luckily I found some comments about the
> exactly some issue on the Mail Archive.(Re: QMI CID leaks
> (
> In this post, it is said that "it looks like this could be fixed most easily in qmi-proxy. I will post a patch candidate for review/merging to libqmi project soon..." But we have investigated the latest version of MM, it seems that this issue remained unfixed.

That specific issue was fixed in commit
16383670dcb471d6a5b802a9cca1e2a24eb86de5, already released in libqmi 1.26.0.

> So I wonder whether this issue have been fixed by your team. If it is, can you please share with us the correct version to use(maybe we have used the wrong version). Or do you have any suggestion to solve this issue? We will appreciate a lot if you can kindly share with us.

Your issue has probably nothing to do with the issue you referenced.
Please open a new issue in gitlab:
And explain exactly what is happening in your setup, which versions of libqmi and MM you're using, and how to reproduce the problem, if any specific way. Please provide debug logs of both qmi-proxy and ModemManager, see


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