Will modem inhibition truly release MBIM port ?

Aleksander Morgado aleksander at aleksander.es
Fri Sep 11 07:46:58 UTC 2020

Hey Edward,

>                        We are now implementing qualcomm device update (qdu) MBIM device service on the libmbim currently used by the MM and fwupd.
>                        It uses the MBIM_SERVICE_INTEL_FIRMWARE_UPDATE service.

Are you using the "Modem Reboot" command only? Or something else?

>                        We found the update process will succeed only if the modemmanager is stopped and the mbim port is opened without the proxy.
>                        Probably the mbim interface could not be interfered during the update process.

You need to investigate why that happens, because it doesn't make much
sense. It is true that the MBIM session is kept open by the proxy, but
other than that, there is no other interaction triggered by the proxy
itself, the only interactions done by the proxy are triggered by
connected clients.

If your client connects to the proxy, you should be able to send
messages without any problem.

>                        Could we stop the mbim-proxy during update and restart it after update ?

That is currently not possible, stopping the mbim-proxy will break
other firmware upgrade processes, like the one for the DW5821e. If
there is any issue triggered by the proxy itself, we should fix the
proxy, not stop it


More information about the ModemManager-devel mailing list