snd_hda: how to duplicate output

Alexander Motin mav at
Mon Sep 27 14:55:53 UTC 2010

S.N.Grigoriev wrote:
> this is an exerpt from 8.1R detailed Release Notes:
> Multimedia Support
> [snipped]
> The snd_hda(4) driver now supports multichannel (4.0 and 7.1)
> playback support. The 5.1 mode support is disabled now due to 
> unidentified synchronization problem. Devices which supports 
> the 7.1 mode can handle the 5.1 operation via software upmix 
> done by sound(4). Note that stereo stream is no longer duplicated 
> to all ports.
> I'm interesting in what way can I restore the old behaviour, when
> stereo stream is duplicated to the black and grey sound card
> output connectors?

The only way is to change channel mapping (chmap array) for stereo
streams in hdac_stream_setup() function.

Alexander Motin

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