We are trying to setup our EC21 Modem with the ModemManager 1.10.8 (open embedded zeus) and with the kernel 5.4. Randomly it takes the correct primary port, but 1 of 10 times.
defconfig is cofigured like the pdf description says and wwan0 is available and also /cdc-wdm0 is there. With ModemManager —debug it says qmi not availabel after a reset.
The file qmi_wwan_q.c/o isnt installed.
How can I fix this issue?
Which logs would help for debug?
Do you see anything, where indicate the issue? What I see, it is communicating over /dev/cdc-wdm0 but “finishes with QMI port open operation finished”.
With yocto openembedded, the “packagegroup-base” has a RDEPEND for “ofono”.
When you analise on the target who wants to acces the “cdc-wdm0” device with “lsof”, you see dbus and “ofono”. This is the reason for the broken pipes with the modemmanager.
For all yocto developers around there.
Write a packagegroup-base.bbappend with this content:
RDEPENDS_packagegroup-base-3g_remove = "
ofono"
It seems like you’re facing an issue with the EC21 Modem and ModemManager not consistently selecting the correct primary port. Just like configuring cute pipes for the perfect blend of charm and functionality, setting up the primary port requires precision and attention to detail. Ensure the correct kernel drivers are loaded, and check the ModemManager logs for port assignment behavior. Debugging with mmcli and verifying QMI compatibility can also help streamline the setup process.