Re: Boot time configuration of audio devices

[nia <nia%NetBSD.org@localhost>]

On Sat, Apr 17, 2021 at 07:18:31AM +0700, Robert Elz wrote:
> Is it practical to use audiocfg that way, as the likely commands
> (most likely only reasonable commands) to use in /etc/audio.conf
> are "set" and "default", and both of those control a device
> specified by a numeric index, which seems to be something that the
> kerel assigns semi-arbitrarily at boot time ?
> 
> I think audiocfg would need to grow commands to allow the device
> to be specified by name, rather than by index, for this to be
> practical.
> 
> Or perhaps have this script accept the devices by name, convert the
> name to index using the output of "audiocfg index" and then use the

The existing mixerctl rc script uses the same kernel-provided
device IDs, but works by saving device-specific settings on shutdown 
and reading them on boot for each device, so might be safer. We could
do this, since I think the "default" command has less value anyway.

We could also adjust audiocfg(1) to generate IDs in a more reproducible
way. I think this is a good idea, but I'm not really sure how to proceed.
Maybe hashing the contents of struct audio_device would be possible, but
we'd need to make sure no drivers would return dplicates if you have two
of the same sound card.