how to mount debugfs -- where is it?

General Discussion
,
1

I’m trying to generate a USB test pattern, following the procedure outlined in this document
7115.UsbgeneralpageLinuxCore - Texas Instruments Wiki.pdf (360.7 KB)

It doesn’t seem to work.

Where do I find the debugfs that I"m supposed to mount? and, do I need to mount this fs in order to run the usb patterns?

I understand too that the different testmodes are under the /usb/ directory ,but, I still can’t seem to run these.

Thank you,

2

Our images have debugfs mounted by default.

The real issue your probably facing, both interfaces are actually active…

One being the usb-host port, the other being the usb-gadget…

You can disable usb-gadget via:

sudo systemctl disable bb-usb-gadgets.service

and reboot…

BUT based on your previous posts you are using usb-serial gadget, hence above will disable that…

So make sure to grab an external usb-serial converter. : Beagleboard:BeagleBone Black Serial - eLinux.org

3

thank you. If I want to latet reenable usb-gadget, how would I do that?

Also, do I need menuconfig? because I can’t seem to make it…

thank you

4

To re-enable:

sudo systemctl enable bb-usb-gadgets.service

If you want menuconfig, you don’t need it… Grab this git branch from this project that builds our shipping kernel. (do it on x86, it’s clones kernel.org, so will take a few GB’s…)

git clone -b ti-linux-5.10.y https://openbeagle.org/RobertCNelson/ti-linux-kernel-dev.git
cd ./ti-linux-kernel-dev/
./build_deb.sh

Regards,

5

ok, thanks. I was finally able to get something working!
I needed to be in root and not in debian. After doing

sudo su

the command
echo "test packet" > /sys/kernel/debug/usb/musb-hdrc.1/testmode

worked.

Thank you for you help!