[alsa-devel] [PATCH 0/30] ALSA: HDA VIA: patch series

[Takashi Iwai]

At Tue, 13 Oct 2009 21:52:02 -0600,
Robert Hancock wrote:
> 
> On Tue, Oct 13, 2009 at 3:40 AM,  <LoganLi at viatech.com.cn> wrote:
> >> >> > What is the problem, specifically?
> >> >>
> >> >> With the latest patch I do get the optical output lighting
> >> up and the
> >> >> receiver detects a PCM signal, but it seems to be just
> >> silence coming
> >> >> through. (In previous iterations the SPDIF digital converter wasn't
> >> >> being enabled automatically so it didn't get even that far.)
> >> >
> >> > You can fiddle with hda-verb to issue digital-converter verbs.
> >> > Possibly you need to flip the digital-enable bit to send
> >> the values...
> >>
> >> Well, I think I tried all combinations of the flags on the digital
> >> converter in hda_analyzer without any luck. I'm assuming it's
> >> something else (presumably codec-specific) that hda_analyzer doesn't
> >> know about..
> >>
> >
> > Hi, Robert
> >  We cannot duplicate bug of SPDIF Out cannot work on VT1828S board.
> >  You said it's fine in Windows, right?
> 
> Ahh, I see the problem. I think it's related to what we were talking
> about with the second SPDIF output: If I play back on subdevice 1 I
> don't get any output. But if I force playing on substream 1 instead of
> the default 0 (i.e. hw:0,1,1) then I get audio. I'm assuming that
> substream 0 is the codec's HDMI output (which actually doesn't exist
> on this motherboard).
> 
> It appears whether or not the "iec958" alias that PulseAudio uses when
> selecting "Output Digital Stereo" profile actually ends up using
> substream 1 instead of 0 is based on luck. as it sometimes works and
> sometimes doesn't. Having different substreams go different places is
> pretty non-intuitive and it seems software doesn't expect this
> behavior. I think that the SPDIF and HDMI outputs really should be
> separate subdevices (i.e. hw:0,1 and hw:0,2 or something) instead,
> unless something makes this impossible. If the aliases for iec958 and
> hdmi were set up to point to the correct subdevice then everything
> would work as it should..

Yes, it's possible to assign two different devices if the pin-config
of each digital output is set up properly for SPDIF and HDMI.
It won't be too difficult to fix, but I have little time now.

BTW, I'll be off from tomorrow for a while (two weeks) to attend
conferences in Tokyo and a few days battery-charging there.
So replies will be delayed.


thanks,

Takashi