[alsa-devel] alsactl adds volume controls?

David Henningsson david.henningsson at canonical.com
Fri Aug 27 20:36:11 CEST 2010

2010-08-27 17:43, Clemens Ladisch skrev:
> David Henningsson wrote:
>> So I've discovered that my sound card has a "PCM Playback Volume"
>> control, but changing that control does not alter the volume.
>> Interestingly enough, this control does not come from the HDA parser, it
>> is added by alsactl at boot time...!
> This control was created by the software volume plugin.  When not using
> this plugin, the control does not have any effect.
> To get rid of it, delete its entry from /etc/asound.state.

Hmm, I wonder if this is an Ubuntu-specific bug then? Because when I run
Maverick (the upcoming Ubuntu release) from a Live-CD, the "PCM Playback
Volume" control is still there (and there is no asound.state, neither in
/etc or in /var/lib/alsa).
When I use the plughw interface, the "PCM Playback Volume" does not
affect volume output. Should I use another device string to test the
softvol plugin, to see if it's there or not?

Btw, I still think it's strange that a userspace plugin, with controls
that only effects userspace, still can create controls in kernel-space.
Am I missing something?

David Henningsson, Canonical Ltd.

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