Dennis HilkLinux diagnosticsDE

Audio devices

USB MIDI streaming interfaces

A MIDI interface transports musical events and can work without any PCM playback device.

Editorial source review: Share public profileOpen in the identification tool
On this page
  1. Overview & identity
  2. Driver & binding
  3. Firmware
  4. Read-only diagnostics
  5. Limitations & related issues
  6. References

Overview & identity

Audio class 01 includes more than audible PCM streams. MIDIStreaming subclass 03 is the relevant descriptor here; a device with only MIDI endpoints is not a missing-speaker diagnosis.

This is an explicit class, transport or driver-context profile. It is not an exact numeric product match.

A numeric match establishes a candidate family within the reviewed evidence. Marketing names, board variants, subsystem conditions and successful operation remain separate questions.

Driver & binding

snd_usb_audio covers generic USB MIDI as well as USB PCM, with MIDI implementation in the checked midi.c path. The quirk table also has a class/subclass MIDI entry. ALSA sequencer clients and raw MIDI endpoints are different from aplay’s PCM list.

  • snd_usb_audio — kernel driver/module candidate

Detected, bound, operational: learn the difference

Firmware

Device/revision dependent

No external firmware filename was established in the checked driver path. This does not describe firmware stored inside the device.

Inspect firmware packaging on your distribution

Read-only diagnostics

Run one displayed command at a time. Replace uppercase placeholders with the affected device, interface or module from your own output. Commands are never executed here. Read-only output can still contain private identifiers.

Inspect interfaces and negotiated speed

lsusb -t

This read-only usbutils query normally needs no sudo. Driver belongs to the displayed interface, while speed is the negotiated connection. Other interfaces of the same physical device may use other drivers.

List raw MIDI endpoints

amidi -l

Use the alsa-utils listing without sudo. It only lists raw MIDI endpoints and sends no events; an absent endpoint is separate from an unloaded ALSA sequencer or the application’s chosen port.

Limitations & related issues

A driver match does not select an application’s MIDI input, synth or channel map. The read-only listing does not send MIDI events, test timing or confirm a vendor-specific protocol.

These guides are linked for relevant observations, not as known defects of every device in this family.

Choose a hardware diagnostic workflow · Inspect a log excerpt in Fix Lab

References

Source review records a checked implementation or document, not a reproduced hardware test. Version-specific tables do not establish a minimum kernel or guaranteed operation.