USB MIDI 2.0 Descriptors

[symdeb]

This is output from lsusb on Ubuntu 22.04.01. This is a prototype MIDI 2.0 (UMP) USB device using alternate setting 1 descriptors Descriptor type 37 subtype 2 is supposed to list bNumGrpTrmBlock but it shows MIDIJack. Reference: USB Device Class Definition for MIDI Devices, Version 2.0 p.42. Not sure where to post this. Only could find this github repo with libusb sources Have no reference to other devices as a comparison (no such devices seem to exist yet).

[symdeb]

MIDI_2_Alt_setting_1.txt

[gregkh]

This is the correct repo, yes.

I don't understand the problem here, what does the output show and what should it show exactly?

[symdeb]

This is what the tool reports:

    MIDIStreaming Endpoint Descriptor:
      bLength                 5
      bDescriptorType        37
      bDescriptorSubtype      2 (Invalid)
      bNumEmbMIDIJack         1
      baAssocJackID( 0)       1

This is what SubType2 per the USB specification should report:

https://www.usb.org/document-library/usb-class-definition-midi-devices-v20

[gregkh]

Thanks for the info, should now be fixed in the tree in commit f7cb6bcf153d ("lsusb: fix up Midi Device specification devices")

Can you pull the latest tree and build and test it to verify?

[symdeb]

git checkout f7cb6bc HEAD is now at f7cb6bc lsusb: fix up Midi Device specification devices The "invalid" message is gone but the field names are not updated : bNumEmbMIDIJack , baAssocJackID( 0)

[symdeb]

Posted a pull request for this.