On Sun, 2005-04-24 at 03:30 +0000, viktor@netbsd.se wrote:
> >Synopsis:       Soundcard is not by default in full-duplex mode, and
>  causing trouble with skype and possible other applications using full
>  duplex feature.

I'm able to reproduce this issue on my test system. Looks like the bug
has existed for over 7 years.

Looking at some of the Linux OSS code, it seems that they default the
audio device to full-duplex mode if the device was opened read/write. We
currently don't do this (it's commented out in sys/dev/audio.c):

        sc->sc_full_duplex = 0;
/* doesn't always work right on SB.
                (flags & (FWRITE|FREAD)) == (FWRITE|FREAD) &&
                (hw->get_props(sc->hw_hdl) & AUDIO_PROP_FULLDUPLEX);
*/

Proposal to change this odd behaviour was sent to tech-kern; waiting for
feedback.

Cheers,
Jared