Hey, > >> I'm using a Quectel EC21 modem on a Debian Buster Linux system (using > >> modemmanager 1.10.0). > >> > > Please note, MM 1.10.0 is a very very old release, no longer > > supported, and it's not even the last one inthe 1.10.x series... > > Fair enough, but 1.10.0 is comes with Debian Buster, which is the latest > Stable release of Debian. However there is a backport of 1.14, from the > Unstable (next release) distro, for Buster. >
1.10.0 was released in 2019-01-17, and after that there have been 4 new updates in the 1.10.x series (1.10.2 on 2019-06-10, 1.10.4 on 2019-07-04, 1.10.6 on 2019-09-12, 1.10.8 on 2019-10-30. Then we have had the whole 1.12.x series up and running (7 releases); 1.12.0 was released on 2019-11-06 and the last 1.12.12 was released on 2020-06-23. 1.14.0 was released on 2020-06-23. You should probably poke Debian Buster packagers of ModemManager... they are 12 releases late in their latest stable release ;) > >> I want to force it to one of 3G or 4G to stop it changing/swapping between > >> the two. > >> > >> I've tried using the `mmcli -m 0 --set-allowed-modes=3g > >> `. mmcli seems happy with that. > >> > >> However, some time later it swaps over to 4G (lte) > >> > >> -------------------------------- > >> Status | lock: sim-pin2 > >> | unlock retries: sim-pin (3), sim-pin2 (3), sim-puk > >> (10), sim-puk2 (10) > >> | state: connected > >> | power state: on > >> | access tech: lte <<< 4G !!! > >> | signal quality: 63% (recent) > >> -------------------------------- > >> > >> > >> Have I got the right expectations of the `--set-allowable-modes` feature? > >> > >> Is there something else I need to do? > >> > > This may be a known issue with QMI modems where the internal network > > registration attempt is done with "QMI NAS Register In Network"; this > > command not only registers in network, it also makes the access tech > > preference fallback to "any", and MM doesn't consider that in its API. > > > > There is a recent patch to avoid this, by avoiding the use of "NAS > > Register in Network" and use "NAS Set System Selection Preference" > > instead: > > https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/commit/c70b3557184fdf1472ff0cb36e9fd937cc7f9024 > > > > That patch is not yet in any release, though, not even in 1.14.0. I'll > > backport it to the 1.14.x branch so that it gets into 1.14.2. > > > > You can confirm that this issue is happening to you by running this > > command once the tech went back to the one you didn't want: > > $ qmicli -d /dev/cdc-wdm0 -p --nas-get-system-selection-preference > > Here is the output. > > # qmicli -d /dev/cdc-wdm0 -p --nas-get-system-selection-preference > [/dev/cdc-wdm0] Successfully got system selection preference > Emergency mode: 'no' > Mode preference: 'umts, lte' > Band preference: 'wcdma-2100, wcdma-850-us' > LTE band preference: '1, 3, 5, 7, 28' > TD-SCDMA band preference: '(null)' > Roaming preference: 'any' > Network selection preference: 'automatic' > Service domain preference: 'cs-ps' > GSM/WCDMA acquisition order preference: 'wcdma' > Acquisition order preference: lte, umts, gsm, td-scdma, > cdma-1x, cdma-1xevdo > > What are the key indicators that confirm the issue? > Network selection preference: 'automatic'??? > Acquisition order preference: lte, umts, gsm, td-scdma, > cdma-1x, cdma-1xevdo??? > Mode Preference (umts + lte) already tells you that the setting was reseted (assuming you requested 3G-only). The SSSP patch in network registration will very very likely solve your problems. -- Aleksander https://aleksander.es _______________________________________________ ModemManager-devel mailing list ModemManager-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/modemmanager-devel
