snd_hda: how to duplicate output

[S.N.Grigoriev]

Hi list,

this is an exerpt from 8.1R detailed Release Notes:

2.2.2.1 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?

Thanks,
Serguey.