[Midnightbsd-cvs] [MidnightBSD/src] 699dde: Add support for multiple playback and recording

[Lucas Holt]

  Branch: refs/heads/master
  Home:   https://github.com/MidnightBSD/src
  Commit: 699ddebf52d5906a86251c94b4c23f079d078597
      https://github.com/MidnightBSD/src/commit/699ddebf52d5906a86251c94b4c23f079d078597
  Author: Lucas Holt <luke at foolishgames.com>
  Date:   2020-11-21 (Sat, 21 Nov 2020)

  Changed paths:
    M sys/dev/sound/usb/uaudio.c
    M sys/dev/sound/usb/uaudio.h
    M sys/dev/sound/usb/uaudio_pcm.c

  Log Message:
  -----------
  Add support for multiple playback and recording
devices per physical USB audio device. This requires some structural
refactoring inside the driver, mostly about converting existing audio channel
structures into arrays.

The main audio mixer is provided by the first PCM instance.
The non-first audio instances may only have a software mixer for PCM playback.

Obtained from: FreeBSD