[alsa-devel] alsactl adds volume controls?

Clemens Ladisch clemens at ladisch.de
Thu Sep 2 17:52:59 CEST 2010

Jaroslav Kysela wrote:
> On Thu, 2 Sep 2010, Clemens Ladisch wrote:
> > What is the reason for alsactl not trying to restore inactive controls?
> Most (maybe all - need to check drivers) of inactive control values are
> reset to the original value when they're going to the active state.

(There are both kinds of inactive controls.)

It wouldn't hurt to restore controls that will be reset later.

> Maybe we need to add another flag - inactive but persistent.

This is more or less implied by the current documentation:
/* control does actually nothing, but may be updated */

I'd rather add a flag for controls that will be reset by the driver,
because this is an action that is done in addition to the 'normal'
control behaviour.

One could also say that inactive controls that will be reset have a
value only as long as they are active, i.e., while inactive, there is
no current value.  In other words, while inactive, they should be
neither readable nor writable.  (Hmm, one could make them just readonly
to avoid problems due to unexpected error codes in mixer applications,
but the last value that it had before becoming inactive isn't likely to
be interesting to anyone.)


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