[Development report #21] Audio Stack Improvements

From: Christos Margiolis <christos_at_freebsd.org>
Date: Tue, 24 Sep 2024 18:39:37 UTC
Attended EuroBSDCon 2024 in Dublin, Ireland:
    - Gave a talk at the FreeBSD DevSummit. Slides:
      https://papers.freebsd.org/2024/eurobsdcon/christos-state-of-the-freebsd-audio-subsystem/
    - Met and discussed with lots of people, some new as well.
    - Gave a "BSD Now" interview regarding the project.

Working on a large patch to get rid of VCHAN pre-allocation and instead
allocate them on-demand. Related discussion:
https://reviews.freebsd.org/D46520

sound: Use unr(9) to produce unique channel unit numbers:
https://reviews.freebsd.org/D46680

sound: Use bus_topo_lock() where needed:
https://reviews.freebsd.org/D46700

snd_dummy: Drain callout during detach:
https://reviews.freebsd.org/D46715

sound: Move global variable initialization to sound_modevent():
https://reviews.freebsd.org/D46749

Working on AFMT_FLOAT support:
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=281390

Submitted 2024Q3 report.

Did some research on SOF.

Did some sound-related bug triaging.

Reviewed
https://cgit.freebsd.org/src/commit/?id=bbf71b31596719c61d540513da3d8a3db20dad66

This work is sponsored by the FreeBSD Foundation.

Christos