EM7305 - Linux Mint 20.1 issues (ttyUSB1-2 interfaces missing)


I’m trying to get EM7305 device working under newer (Debian based) Linux Distribution with modern kernel revision. Computer model which I’m using is a Panasonic Toughpad FZ-M1 mark3.

EM7305 firmware revision is: SWI9X15C_05.05
Mint 20.1 is running kernel: 5.4.0-58-generic #64-Ubuntu SMP
Linux QMI Driver (Sierra Wireless): Version S2.42N2.64

So far, I have managed to compile the latest SierraQMIdrivers without any issues and
GobiSerial plus GobiNet modules are seems to be loaded OK by the kernel, but the main problem is that there’s still just one single ttyUSB0 device present under /dev/. Other ttyUSB ports are missing.

here is my dmesg output:
[ 10.951174] GobiNet: loading out-of-tree module taints kernel.
[ 10.968375] GobiNet: 2020-08-17/SWI_2.64
[ 10.968533] usbcore: registered new interface driver GobiNet
[ 11.005850] usbcore: registered new interface driver GobiSerial
[ 11.005871] usbserial: USB Serial support registered for GobiSerial
[ 11.005926] GobiSerial: 2020-08-17/SWI_2.42:GobiSerial

under /dev/ there is also /dev/cdc-wdm1 which seems to respond ok to any queries.

I also tested Ubuntu 20.04 LTS on this system and it was pretty much similar result: only ttyUSB0 present under /dev.

EM7305 works nicely as LTE-modem on these systems (Ubuntu 20.04 / Ḿint 20.1), but I need the get the GPS/GNSS function working as well.

I would appreciate any suggestions/tips how to get this system to recognize other ttyUSB1 and ttyUSB2 interfaces on Linux, that I could communicate with those interfaces on this EM7305 device.

It should have just worked by default without installing any driver, using ModemManager + NetworkManager to manage the device.

But this will be broken after installing the Gobi drivers.

Then you didn’t follow the GobiNet instructions. You either need to remove all the Gobi stuff or install it properly according to instructions from Sierra Wireless.