[alsa-devel] dmix problems with analog out (HDMI out works fine with dmix)

Robert Krakora rob.krakora at messagenetsystems.com
Thu Sep 29 14:43:32 CEST 2011


On Thu, Sep 29, 2011 at 8:32 AM, Takashi Iwai <tiwai at suse.de> wrote:

> At Thu, 29 Sep 2011 08:22:39 -0400,
> Robert Krakora wrote:
> >
> > On Thu, Sep 29, 2011 at 2:36 AM, Takashi Iwai <tiwai at suse.de> wrote:
> >
> > > At Wed, 28 Sep 2011 12:29:05 -0400,
> > > Robert Krakora wrote:
> > > >
> > > > Hi All,
> > > >
> > > > I am using ALSA 1.0.24 with the attached asound.conf.  I am
> attempting to
> > > > share (mix) the analog output between Asterisk and aplay.  However,
> when
> > > > Asterisk is running, my application throws an error when attempting
> to
> > > play
> > > > a wave file via aplay.  If I stop Asterisk, aplay plays the wave file
> > > just
> > > > fine.  If I remove the asound.conf file, Asterisk and aplay are both
> > > happy
> > > > and share the analog output just find with the default ALSA dmix
> > > > implementation.  However, we need this asound.conf to work for us for
> > > other
> > > > reasons.  What is wrong with it.  I have even tried replacing dmix
> with
> > > > dshare and get the same bad behavior.  We are running CentOS 6.0.  As
> a
> > > > caveat, I am attempting to use dmix with analog audio.  If I use it
> with
> > > > HDMI audio, it works flawlessly (same asound.conf with tweek to
> specify
> > > > HDMI).  Thanks in advance for your help.
> > > >
> > > > [root at devkrakorar snd]# su silentm -c "aplay -Dplug:dmixer
> > > > /usr/share/sounds/alsa/Front_
> > > > Center.wav"
> > > > ALSA lib pcm_hw.c:1293:(snd_pcm_hw_open) open '/dev/snd/pcmC0D0p'
> failed
> > > > (-22): Invalid argument
> > > >
> > > > ALSA lib pcm_dmix.c:1068:(snd_pcm_dmix_open) unable to open slave
> > > > aplay: main:660: audio open error: Invalid argument
> > > > [root at devkrakorar snd]#
> > >
> > > Looks like the open of HD-audio stream failed by some reason.
> > > When you open via aplay, is the corresponding stream already opened
> > > by another?  Take a look at /proc/asound/card0/pcm0p/sub0/* files.
> > >
> > > Also, try the latest alsa-driver snapshot in
> > >   ftp://ftp.suse.com/pub/people/tiwai/snapshot/
> > >
> > >
> > > Takashi
> > >
> >
> > Hi Takashi,
> >
> > Thanks for the quick response.  Yes, the HD-audio stream open fails
> because
> > Asterisk has previously opened it.  aplay cannot open it (error -22).
>
> -22 is -EINVAL, and it's not -EBUSY or -EAGAIN.  If a blocking open is
> the problem, it should have been -EAGAIN or such.
> That is, usually something conflicts with the opened stream.
>
>
> Takashi
>

Hi Takashi,

You are the man!  Your latest drivers have eliminated this issue!  What did
you have to change to fix this?

Best Regards,

-- 
Rob Krakora
MessageNet Systems
101 East Carmel Dr. Suite 105
Carmel, IN 46032
(317)566-1677 Ext 212
(317)663-0808 Fax


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