Functionality of pcm_notify in snd-aloop?

[Pavel Hofman]

Dne 26. 03. 20 v 18:59 Pavel Hofman napsal(a):
> Dne 26. 03. 20 v 18:44 Jaroslav Kysela napsal(a):
>> Dne 26. 03. 20 v 18:19 Pavel Hofman napsal(a):
>>> Hi,
>>>
>>> Please how is the module params pcm_notify supposed to be used, to do
>>> what the documentation says: Break capture when PCM format/rate/channels
>>> changes?
>>>
>>> Breaking capture side operation when the playback side changes the
>>> params is very useful, but I cannot find a way to use this param
>>> properly. When the capture side is open, the playback side cannot use a
>>> different parameter than the one currently used by the capture side (the
>>> configuration space is limited)
>>
>> Really? Then it's a bug introduced by the last changes.
>>
>> If you look to sources:
>>
>>       if (get_notify(dpcm))
>>                 runtime->hw = loopback_pcm_hardware;
>>         else
>>                 runtime->hw = cable->hw;
>>
>> And:
>>
>>       if (!(cable->valid & ~(1 << substream->stream)) ||
>>             (get_setup(dpcm)->notify &&
>>              substream->stream == SNDRV_PCM_STREAM_PLAYBACK))
>>                 params_change(substream);
>>
>> So the functionality should be there.
> 
> I am using older kernels (4.15 and 3.16), but this is an old functionality.
> 
> modprobe snd-aloop pcm_substreams=1 pcm_notify=1,1
> 

Please is there any way to solve this issue? Thanks a lot for your patience.

Best regards,

Pavel.