list of linux kernel modules loaded on my machine (for later perusal and research)

[pestophagous]

$ lsmod | grep snd_

snd_usb_audio         180224  1
snd_usbmidi_lib        36864  1 snd_usb_audio
snd_seq_dummy          16384  1
snd_hda_codec_realtek    90112  1
snd_hda_codec_generic    77824  1 snd_hda_codec_realtek
snd_hda_intel          40960  5
snd_hda_codec         135168  3 snd_hda_codec_realtek,snd_hda_codec_generic,snd_hda_intel
snd_hda_core           77824  4 snd_hda_codec_realtek,snd_hda_codec_generic,snd_hda_codec,snd_hda_intel
snd_hwdep              16384  2 snd_usb_audio,snd_hda_codec
snd_pcm               106496  5 snd_usb_audio,snd_hda_codec,snd_hda_intel,snd_hda_core
snd_seq_midi           16384  1
snd_seq_midi_event     16384  1 snd_seq_midi
snd_rawmidi            32768  2 snd_usbmidi_lib,snd_seq_midi
snd_seq                69632  8 snd_seq_midi_event,snd_seq_dummy,snd_seq_midi
snd_seq_device         16384  3 snd_seq,snd_rawmidi,snd_seq_midi
snd_timer              32768  2 snd_pcm,snd_seq
snd                    86016  22 snd_hda_codec_realtek,snd_usb_audio,snd_hwdep,snd_timer,snd_pcm,snd_seq,snd_rawmidi,snd_hda_codec_generic,snd_usbmidi_lib,snd_hda_codec,snd_hda_intel,snd_seq_device

when further filtered on "midi"

snd_usbmidi_lib        36864  1 snd_usb_audio
snd_seq_midi           16384  1
snd_seq_midi_event     16384  1 snd_seq_midi
snd_rawmidi            32768  2 snd_usbmidi_lib,snd_seq_midi
snd_seq                69632  8 snd_seq_midi_event,snd_seq_dummy,snd_seq_midi
snd_seq_device         16384  3 snd_seq,snd_rawmidi,snd_seq_midi
snd                    86016  22 snd_hda_codec_realtek,snd_usb_audio,snd_hwdep,snd_timer,snd_pcm,snd_seq,snd_rawmidi,snd_hda_codec_generic,snd_usbmidi_lib,snd_hda_codec,snd_hda_intel,snd_seq_device

[pestophagous]

[pestophagous]

https://webcache.googleusercontent.com/search?q=cache:https://andrewnicolaou.co.uk/posts/2016/pi-zero-midi-3-two-things-at-once

https://www.kernel.org/doc/html/latest/usb/gadget-testing.html

USB peripheral mode

To enable MIDI for USB peripheral mode, you may need to apply patches to your Linux kernel to integrate drivers/usb/gadget/f_midi.c into the USB gadget driver. These patches are available for Linux kernel version 3.10. These patches have not yet been updated for ConfigFs (a new architecture for USB gadget drivers), nor are they merged at upstream kernel.org.

The patches are shown in commit order for the kernel tree at project kernel/common branch android-3.10:

    https://android-review.googlesource.com/#/c/127450/
    https://android-review.googlesource.com/#/c/127452/
    https://android-review.googlesource.com/#/c/143714/

moddevices/linux-rk3399-graperain@3dae85a

moddevices/linux-mainline@24cf345