u-blox LARA0-R2 (R280) not worrking with MM 1.10

[Lars Melin]

On 4/29/2019 11:12, Brendan Simon (eTRIX) wrote:
> I can't get the u-blox LARA R2 device working with ModemManager 1.10.
> 
> I've tried a Debian Buster (aka Testing) distro that uses ModemManager 
> 1.10 (and kernel 4.19).  The serial devices are present but `mmcli -L` 
> does not show any modems.
> 
> I've also tried the latest Ubuntu 19.04 Disco release (VM image from 
> osboxes.org).  It also has ModemManager 1.10 (and kernel 5.0.0) and it 
> also does not work.  i.e. the serial devices are present but `mmcli -L` 
> does not show any modems.
> 
> The only system that I've got to work is Ubuntu 18.10 Cosmic, which uses 
> ModemManager 1.8.2 (and kernel 4.18.0).
> 
> My guess is that something is broken in ModemManager 1.10 (or some 
> related package or dependency).  Can someone confirm that please. Is 
> there anything I can do to test or provide debug info for this. I need 
> to get this working with Debian Buster and MM 1.10.
> 
> Thanks,
> Brendan.
> 

Check your dmesg log for creation of ttyACM devices right after the LARA 
R2 is found and probed on the USB bus, you should get 5 of them.

If not then check that cdc_acm is loaded (lsmod) it may have been 
compiled into the kernel in the working system but may have been 
compiled as a module in the non-working systems in which case you have 
to manually load it with "modprobe cdc_acm".

When you have the ttyACM devices and it still doesn't work then is the 
time to check what modemmanager does, the kernel or networkmanager is 
the least likely to be the cause of your problem.