Re: [Development report #1] Audio Stack Improvements

From: Florian Walpen <>
Date: Thu, 11 Jan 2024 18:38:21 UTC
Hi Christos

That's a good start. Having model names for USB audio devices sure helps! 
Since snd_uaudio gets some attention and testing, it may be an opportunity to 
have a look at
This patch addresses frequent CPU wakeups (power consumption) with the default 
settings, eliminates unnecessary playback latency (video calls) and makes low 
latency operation possible if desired (live music effects).


On Tuesday, January 9, 2024 6:00:41 PM CET Christos Margiolis wrote:
> The past (and first) week working on the audio stack, sponsored by the
> FreeBSD Foundation, I:
> - Set up my development environment; a VM image running -CURRENT in
>   bhyve with PCI-passthru enabled to do all of the driver (kernel
>   generallly) development in the VM.
> - Wrote a small series of patches for
> - Modified the snd_uaudio(4) driver to provide information about the
>   sound card (manufacturer, model and attached driver), as opposed to
>   the current generic "USB Audio" string, so /dev/sndstat and programs
>   like mixer(8) can output more useful information about USB audio
>   devices.
> - Submitted a patch to update (and unify) the description format for all
>   sound devices, since some of them haven't been touched for years.
> - Implemented device_set_descf() , a printf-like version of
>   device_set_desc().
> - Was preparing a few more smaller patches.
> - Started looking into possible solutions to
>   also mentioned in the first paragraph of the BUGS section of the
>   snd_uaudio(4) man page.
> Christos