> I think the author of CS4231 intended to make the
> built-in the speaker mutable by CSAUDIO_MONITOR_MUTE.
> However, CSAUDIO_MONITOR_MUTE doesn't work for the
> internal speaker of Ultra 1.

The same is true for cs4231 audio in U5s and Krups (JavaStation).

> With the attached fix, 'mixerctl -a -v' will show additionally,
> 
> 	monitor.master.mute=off  [ off on ].
> 
> The built-in speaker can be turned on or off with this.

I like this.

I would suggest a further change: currently cs4231 uses the
"monitor" class for all output related settings. I'd like to replace that
with "outputs", which I find more natural (and IIRC which matches other audio
drivers).

Any objections to commit Sung-Won Chungs patch and/or the rename?

Martin