[alsa-devel] limitations on number of alsa controls for a card

Takashi Iwai tiwai at suse.de
Fri Nov 2 10:00:57 CET 2012

At Thu, 01 Nov 2012 20:16:51 +0530,
Vinod Koul wrote:
> On Thu, 2012-11-01 at 14:25 +0000, Mark Brown wrote:
> > On Wed, Oct 31, 2012 at 07:37:31PM +0530, Vinod Koul wrote:
> > 
> > > Is there any limitation on maximum number of controls we can have.
> > 
> > > I had some platform side controls to represent DSP and adding them made
> > > some of codec controls to vanish. And looks like if I register these
> > > platform controls not all codec controls are visible in userpsace.
> > > Is there nay max limit I am hitting?
> > 
> > Not that I'm aware of beyond sizeof() type stuff which you're probably
> > still a way away from.  How are you listing the controls and are there
> > any name collisons?
> alsa_amixer -c"cardname" controls

Better to use alsactl for obtaining the list of raw control elements.

> if there isn't anything in kernel which limits this, would there be
> something in alsa-lib to have this kind of behavior?

In most cases, such a problem is a driver bug, e.g. creating control
elements conflicting with each other for the mixer abstraction.


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