midi2-dev
GTB returns zeros
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.
Can you please send through the commands you used to create the Linux Gadget? This will help in replicating the issue. Thanks
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.
Just upgraded to Ubuntu 23.10, Kernel 6.8
Tried the gadget from the USB Linux page. Script attached.
it curious why the config descriptors isn't parsed correctly.
Add the lsusb log for the gadget:
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.
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 https://github.com/node-usb/node-usb/issues/749