Question regarding modem

[dcinoz]

whether this could be a hardware problem? Or is that simply impossible given that everything works except for sending text messages?

You might try turning off IMS as some people have reported it being on resulted in sending SMS issues:
https://gitlab.com/mobian1/issues/-/issues/254

Note that if you use a configuration in /etc/eg25-manager/ you need to check that it matches a potentially newer version (after updates) as otherwise it can break things with eg25-manager (/usr/share/eg25-manager/ is where defaults are located).

What carrier are you with? It could be carrier specific: https://wiki.pine64.org/wiki/PinePhone_Carrier_Support
I suppose you have already tried forcing 3G?

Frustrating how it seems to work for some people, not for others, so most likely a carrier issue.

Thanks a lot!

Forcing 3G didn't help. My carrier is O2 Germany; according to the wiki and to my experience it works without problems on other pinephones.

I'm sorry, but I can't really follow the discussion at gitlab. It sounds as if it is worth a try, but what exactly do I have to do? And can I even do it after installing FOSS fimware? (That's something I am not able to revert, but that did not worry me much because it's not the cause anyway: The sending did not work with the preinstalled firmware, it did not work when i reflashed the modem and it does not work now with the FOSS firmware.)

FOSS firmware should not change anything AFAIK in terms of AT commands and hopefully VoLTE / IMS profiles are available in the modem.

I don't know if O2 Germany has enabled VoLTE by default, if you want to investigate VoLTE on the pinephone you can start with:
https://forum.pine64.org/showthread.php?tid=12560
https://wiki.postmarketos.org/wiki/PINE6...one)#VoLTE

Using the latest Mobian and modem manager you can send AT commands to the modem. You can try the "ROW_Generic_3GPP" profile if there is none for O2, there might be more answers on this forum, I don't know. When you receive / make calls do you stay on 4G or do you drop down to 3G. If you stay on 4G then VoLTE works presumably assuming calls work. If you drop to 3G then VoLTE is not enabled / does not work. If your carrier supports it / it is enabled for you SIM / phone (some carriers have whitelists), look at the profile as above and give it a try.
Found this post on O2 Germany and working VoLTE https://forum.pine64.org/showthread.php?...1#pid91201

You can check the IMS/ VoLTE status in Mobian using:
mmcli -m any --command='AT+QCFG="ims"'

Otherwise disable IMS (see commands https://forum.pine64.org/showthread.php?...8#pid85368)
AT+QCFG="ims",2 (Edit: correction not 0 as this is defined by MBN file / profile, 2 is disable, 1 enable)
or via modem manager directly from command line:
mmcli -m any --command='AT+QCFG="ims",2' (Edit: corrected from 0 to 2 as above)
Response 1,0 means IMS enabled but VoLTE not ready
1,1 would indicate enabled in modem and VoLTE ready i.e. you can make 4G calls using VoLTE
2,0 would happen when you have disabled IMS support in the modem (see below) (Edit: corrected to 2,0 if issue above commands, you could possibly get 0,1 or 1,1 also)

Then try text / SMS (note MMS does not work yet as you probably know).

Note that enabling IMS does not mean IMS is working just that the modem will try to enable if if the network supports it and the IMS profile works.

eg25-manager info here:
https://gitlab.com/mobian1/devices/eg25-manager

It sets up the modem on boot based on configuration files in /usr/share/eg25-manager
See the relevant one for you Pinephone version.

This what you need to change to disable VoLTE support:
# Enable VoLTE support
#    { cmd = "QCFG", subcmd = "ims", expect = "1" },
    { cmd = "QCFG", subcmd = "ims", value = "2" },

(Edit: Corrected to 2 as per above to disable IMS function)

Updates can overwrite /usr/share/eg25-manager configuration files so to avoid a custom/modified file from being overwritten you can copy to an eg25-manager directory you create in /etc so that it is stored in /etc/eg25-manager/

Beware that updates in eg25-manager can change the configuration file and break functionality. So any updates to eg25-manager I recommend checking /usr/share/eg25-manager or copying the config file back to /etc/eg25-manager/ and modifying it if need be.

Note that AT+CFUN=1,1 according to Quectel EM12&EG12 and EC25&EC21manuals means full functionality,reset ME. I would understand this as reset to default settings so I would not issue that command at first, see what happens issuing status commands for IMS / testing calls. If that fails issue the command. AT+CFUN=1,0 means full functionality, do not reset the ME.
Test status using AT+CFUN? - default should answer 1 ie full functionality, so I don't know why you would reset? Aldimobile does not VoLTE enabled yet so I can't test it myself.

Write down default modem settings before you change anything so that you can go back.

Hope this helps. The Mobian bug report thread has one person saying disabling IMS support fixed the SMS issue so hopefully that works for you.
But IF VoLTe does indeed work for O2 Germany then hopefully enabling that also fixes the SMS issue!

Let us know.