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

Felix Homann linuxaudio at showlabor.de
Thu Nov 1 18:42:01 CET 2012

2012/11/1 Vinod Koul <vinod.koul at linux.intel.com>:
> 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.
>> Not that I'm aware of beyond sizeof() type stuff which you're probably
>> still a way away from.

At least, for USB devices there's a maximum for logical mixer channels
(currently, MAX_CHANNELS = 16).  This might feel like a limit for the
number of mixer controls depending on the respective mixer topoplogy.
MAX_CHANNELS can't be raised deliberately in the current code since it
is used for some bitshifting. I don't know if something similar exists
for PCI devices

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