[alsa-devel] how to mandate the use of PCM plugin?

[Raymond Yau]

2010/9/28 Stas Sergeev <stsp at aknet.ru>

>  28.09.2010 02:00, Mark Brown wrote:
> > I can't really comment since I've no idea what the problem is; if it's
> > not understood what has gone wrong then some diagnosis will be needed.
> For now, all I can say is that the softvol
> doesn't communicate with pulseaudio when
> snd-pcsp is used. You can alter it, but the
> playback volume won't change. And if you
> run the pulseaudio mixer in parallel, it won't
> reflect the change done by alsamixer too.
>

AFAIK, PA probe "hw" device for mono output profile first .

As snd-pcsp support only mono , PA expect "front" device support stereo so
it cannot create stereo output profile

So it is incorrect to define "front" device to use "hw" without "plug"
plugin  when the pcsp does not support stereo

 http://0pointer.de/blog/projects/decibel-data.html

finally falling back to software for everything that cannot be done in
hardware.