GTB returns zeros

[MusicMaker]

As discussed on Microsoft Discord about a custom MIDi 2.0 device that showed zeros for the GTB in Workbench. There was some doubt about the device. Due to lack of any peer device, tried a Linux USB MIDI 2.0 gadget.

A. How to reproduce:

• Ubuntu 23.10 updated with 6.7.5 kernel and USB gadget support
• Gadget created for MIDI 2.0
• Workbench report as follows:

B. A tool to read the GTB descriptors with libusb returns a correct GTB for the gadget:

C. Conclusion : would think there is an issue in Workbench.

[starfishmod]

Can you please send through the commands you used to create the Linux Gadget?
This will help in replicating the issue.
Thanks

[starfishmod]

I just tried to replicate your issue using a MIDI 2 Gadget and I get:

It seems I'll need your script to create the Linux Gadget to replicate this issue.

[MusicMaker]

Just upgraded to Ubuntu 23.10, Kernel 6.8

Tried the gadget from the USB Linux page. Script attached.

midi2_gadget.sh.txt

it curious why the config descriptors isn't parsed correctly.

Add the lsusb log for the gadget:

gadget_log.txt

[MusicMaker]

Any further ideas?

[starfishmod]

Ok I finally found some of the issue around this.
When I connect:

• Linux Gadget -> OSX = Working as expected
• Linux Gadget -> Linux = (After small fix) Mostly Working - Getting GTB's seems to be odd. I think I might have a race condition
• A88-MK2 -> OSX = Working as expected
• A88-MK2 -> Linux = Same Issue as Linux Gadget

I will keep investigating - however it may be an unsolvable issue for Linux host.

[starfishmod]

Ok I had disabled the getting GTB infomation over LibUSB where the MIDI 2.0 Kernel is used as it always causes an error. See node-usb/node-usb#749