USB modem is not working with own linux

I’m using a ublox SARA-U201 USB modem. With the linux version from toradex it is working. I can start it with pon and have a internet connection. With my own linux version, everytime I start the system, the modem is in air plane mode and even when I change the mode, I can’t get it working. I don’t know, where there is a difference between the to linux. One thing I found is, that with your version, I see “usb0”, when typing “ifconfig”, with mine not.

Do you any suggestion, what to change?

Best regards, PrS

What exactly do you mean by “own Linux version”? May I suggest for you to look at the following article concerning configuration, compilation and deployment of a custom Linux kernel? Please also note that BSP 2.8b2 being an older beta version is no longer supported. You may find more information here.

I build my own linux based on OpenEmbeddedBuild as suggested from your colleague.

As @marcel.tx, you should update to the newest release 2.8b4 and then do the build with included java layer. Once this is done and you still have issues, could you send then a dmesg log in a file? Thanks.

I build a new version:
Linux colibri-vf 4.4.158-2.8.4+g4f5df6d #1 Mon Oct 22 08:15:07 UTC 2018 armv7l GNU/Linux
I still have the same problem. Attached I send you the dmesg text

Dear @PreachersSon

Can you provide some more information? Did you modify the kernel/kernel config or did you modify the Devicetree?


Dear @stefan_e.tx

I changed local.conf and bblayers.conf to add java. I attached the text How can I modify the kernel, when I build it based on OpenEmbeddedBuild?

Best, PrS

hi @PreachersSon

You don’t need to modify the kernel during Openembedded Build. If you just added the java layer, the kernel config should not be changed.

Just for checking: Could you share the dmesg log with your image and the toradex regular bsp image? And the same for the output of lsmod?


Hello @jaski.tx , @stefan_e.tx ,

Attached I send the dmesg log and lsmod output of my own version and of the toradex version. link text

Best, PrS

hi @PreachersSon: Something is wrong with your attached files. I cannot access the link. Could you upload these again, please?

Hi @jaski.tx ,

Here are the files again.
link text
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Thanks for the files. You are comparing 2.8.4 (your own version) with 2.7.4 (toradex version). Could you flash the 2.8.4 from toradex then do the testing, if your usb modem is working correctly?

Hi @jaski.tx ,

With the version
Linux colibri-vf 4.4.158-2.8.4+g4f5df6df46d0 #1 Fri Oct 5 18:00:42 UTC 2018 armv7l GNU/Linux
it is not working. Here are the dmesg and lsmod output of this version.

So this means, the modem is working correctly with Bsp 2.7.4 but not with 2.8.4, regardless with or without Java. As a workaround, you can build a custom image with 2.7.4 with added Java Support.

Concerning your Issue with 2.8.4, how do you setup the USB modem?

Hello @jaski.tx

When I build linux 2.7.4 myself, modem is working, but I’m not able to add Java to the build. error

If the modem is working, I just connect it and call “pon”.

Best, PrS

Thanks for the Information.

Could you share the complete set of commands you launched and the error log of open-embedded build with added Java Layer. I tried it on my side, it works fine.

Hello @jaski.tx ,

Attached I send you the command line in- and output and the local.conf and bblayers.conf text

Best, PrS

Perfect that it works. Thanks for the feedback.

It seems that I found the problem. When I disable ofono service the modem is working and I can establish a connection. Now I have to test, if the connection is really working.