[alsa-devel] increase number of alsa loopback

[Jaroslav Kysela]

Dne 27. 02. 19 v 16:44 Olivier SCHMITT napsal(a):
> Hello,
> 
> Thanks for reply,
> 
> I have configure /etc/modprobe.d/alsa-base.conf with:
> 
> options snd-aloop 
> index=5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29 
> id=lp0,lp1,lp2,lp3,lp4,lp5,lp6,lp7,lp8,lp9,lp10,lp11,lp12,lp13,lp14,lp15,lp16,lp17,lp18,lp19,lp20,lp21,lp22,lp23,lp24 
> enable=1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1 
> pcm_substreams=2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2
> 
> but when i use index more than 32, i have some message in syslog that 
> it's say alsa can't use index greather than 32...
> 
> Maybe have your an idea for modify et recompiling kernel?

I'm afraid, the ALSA card limit (32) is hardcoded and cannot be easily
changed. The recompilation won't help.

You may use up to 8 pcm substreams per the loop card. This limit can be
increased by changing the value in aloop.c (kernel driver).

					Jaroslav

> Le 27/02/2019 à 15:35, Jaroslav Kysela a écrit :
>> Dne 27. 02. 19 v 15:20 Olivier SCHMITT napsal(a):
>>> Hello All,
>>>
>>> First, thanks for your project!
>>>
>>> I search to increase the maximum number of 32 alsa loopback.
>>>
>>> Can someone say me how do this?
>> There's hardcoded limit for the PCM substreams to 8, but you may enable
>> more loopback cards (options snd-aloop enable=1,1,1,1).
>>
>> 				Jaroslav
>>


-- 
Jaroslav Kysela <perex at perex.cz>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.