[alsa-devel] In 3.8 kernel alsa only talks HDMI, hardware also has S/PDIF optical

[Takashi Iwai]

At Tue, 12 Mar 2013 15:26:03 +0800,
Raymond Yau wrote:
> 
> > >
> > > On my Asus P8H67-V there really are two physically
> > > separate audio outputs. I have the optical port
> > > connected to my receiver for when I want to pass
> > > through the 5.1 audio tracks in movie files and
> > > DVDs and the HDMI connected to the TV for more
> > > ordinary audio (error beeps from the computer, etc).
> > >
> > > In kernel 3.7.9 I could output to both devices
> > > (one at a time - never tried simultaneous).
> > >
> > > I've seen a bunch of patches in the archives that seem
> > > to be related to this, but if fedora 18 has those patches,
> > > they don't seem to be working.
> >
> > This is an intended change, considered as a "fix" for the formerly
> > broken state.  The combination of SPDIF + HDMI has never been working
> > properly because of conflicting control elements assignment.  (You may
> > say that "it worked for me!", but it doesn't count it gets used right
> > :)
> >
> > For fixing it, one of them has to be victimized.  Now IEC958 control
> > element of SPDIF is shifted to the lone safe place for the sake of
> > HDMI, which has more users than SPDIF, being persistent.
> >
> > Updating alsa-lib configuration from alsa-lib git tree should correct
> > the usage of ICE958 control index for SPDIF devices.  Hopefully we'll
> > get alsa-lib release sometime later...
> >
> >
> 
> Is IEC958 Default PCM Playback Switch specific for analog codec's spdif ?

It's only for the digital output implemented on the same codec for
analog outputs.


Takashi

> control.32 {
> iface MIXER
> name 'IEC958 Default PCM Playback Switch'
> value true
> comment {
> access 'read write'
> type BOOLEAN
> count 1
> }
> }