OSS and multiple soundcards

OSS and multiple soundcards

Post by crow.. » Mon, 13 Feb 2006 15:08:09



Hello,

I am running debian with a 2.6.8 kernel, and I am currently using oss
drivers to play sound.  As the system is running fine as-is, I don't
really want to switch to ALSA unless it's the only alternative.

My box has two identical soundcards installed, but I only seem to be
able to get audio output from one of the two soundcards (the first).
The relevant lspci output follows:

0000:00:0b.0 Multimedia audio controller: Ensoniq 5880 AudioPCI (rev
02)
        Subsystem: Ensoniq Creative Sound Blaster AudioPCI128
        Flags: bus master, slow devsel, latency 32, IRQ 5
        I/O ports at c400 [size=64]
        Capabilities: <available only to root>

0000:00:0d.0 Multimedia audio controller: Ensoniq 5880 AudioPCI (rev
02)
        Subsystem: Ensoniq Creative SoundBlaster AudioPCI 128
        Flags: bus master, slow devsel, latency 32, IRQ 11
        I/O ports at c800 [size=64]
        Capabilities: <available only to root>

Though the two cards do seem slightly different (I/O ports at c400 vs.
c800, whatever that means...) as far as I can tell the es1371 driver is
the preferred one for both cards.  As I said, I can get sound output
fine from the first soundcard (/dev/dsp), but the second one seems to
be slient.

I am wondering also what the /dev/dsp* devices refer to.  Should
/dev/dsp refer to the first card and /dev/dsp2 the second?  If so, I
cannot configure the device with aumix, and mplayer indicates that
/dev/dsp2 does not exist.

Are there any configuration issues involved with trying to use two
identical soundcards on the same system?

Thanks for any advice.

 
 
 

OSS and multiple soundcards

Post by Henrik Carlqvis » Mon, 13 Feb 2006 20:05:42



> I am wondering also what the /dev/dsp* devices refer to.  Should
> /dev/dsp refer to the first card and /dev/dsp2 the second?

No, /dev/dsp probably refers to your first card, but /dev/dsp1 is proably
the one that should refer to your second card. The names of the devices
are not important, the important thing is their major and minor numbers.

This is what it looks like on my Slackware 9.1 system. I use ALSA but have
the oss compability module from alsa loaded also.

ls -al /dev/dsp*
lrwxrwxrwx    1 root     root            4 Jan  3  2002 /dev/dsp -> dsp0
crw-rw-rw-    1 root     sys       14,   3 Aug 29  2003 /dev/dsp0
crw-rw--w-    1 root     sys       14,  19 Aug 29  2003 /dev/dsp1
crw-rw--w-    1 root     sys       14,  35 Aug 29  2003 /dev/dsp2
crw-rw--w-    1 root     sys       14,  51 Aug 29  2003 /dev/dsp3

As you can see /dev/dsp is only a symbolic link to /dev/dsp0 on my system.
What different major and minor numbers are connected to is explained in
/usr/src/linux/Documentation/devices.txt. That file says this about OSS:

-8<-------------------------------------------------
 14 char        Open Sound System (OSS)
                  0 = /dev/mixer        Mixer control
                  1 = /dev/sequencer    Audio sequencer
                  2 = /dev/midi00       First MIDI port
                  3 = /dev/dsp          Digital audio
                  4 = /dev/audio        Sun-compatible digital audio
                  6 = /dev/sndstat      Sound card status information {2.6}
                  7 = /dev/audioctl     SPARC audio control device
                  8 = /dev/sequencer2   Sequencer -- alternate device
                 16 = /dev/mixer1       Second soundcard mixer control
                 17 = /dev/patmgr0      Sequencer patch manager
                 18 = /dev/midi01       Second MIDI port
                 19 = /dev/dsp1         Second soundcard digital audio
                 20 = /dev/audio1       Second soundcard Sun digital audio
                 33 = /dev/patmgr1      Sequencer patch manager
                 34 = /dev/midi02       Third MIDI port
                 50 = /dev/midi03       Fourth MIDI port
-8<-------------------------------------------------

For some reason that file only mentions two "Digital audio", dsp0 and
dsp1.

Quote:> If so, I cannot configure the device with aumix, and mplayer indicates that
> /dev/dsp2 does not exist.

That is probably correct as you only have two soundcards.

Quote:> Are there any configuration issues involved with trying to use two
> identical soundcards on the same system?

Unfortunately I have no experience from using oss or two soundcards.

regards Henrik
--
The address in the header is only to prevent spam. My real address is:
hc7(at)uthyres.com Examples of addresses which go to spammers:


 
 
 

OSS and multiple soundcards

Post by Jan Sevelste » Thu, 16 Feb 2006 19:28:15



> Hello,

> I am running debian with a 2.6.8 kernel, and I am currently using oss
> drivers to play sound.  As the system is running fine as-is, I don't
> really want to switch to ALSA unless it's the only alternative.

> My box has two identical soundcards installed, but I only seem to be able
> to get audio output from one of the two soundcards (the first). The
> relevant lspci output follows:

> 0000:00:0b.0 Multimedia audio controller: Ensoniq 5880 AudioPCI (rev 02)
>         Subsystem: Ensoniq Creative Sound Blaster AudioPCI128 Flags: bus
>         master, slow devsel, latency 32, IRQ 5 I/O ports at c400 [size=64]
>         Capabilities: <available only to root>

> 0000:00:0d.0 Multimedia audio controller: Ensoniq 5880 AudioPCI (rev 02)
>         Subsystem: Ensoniq Creative SoundBlaster AudioPCI 128 Flags: bus
>         master, slow devsel, latency 32, IRQ 11 I/O ports at c800
>         [size=64]
>         Capabilities: <available only to root>

> Though the two cards do seem slightly different (I/O ports at c400 vs.
> c800, whatever that means...) as far as I can tell the es1371 driver is
> the preferred one for both cards.  As I said, I can get sound output fine
> from the first soundcard (/dev/dsp), but the second one seems to be
> slient.

> I am wondering also what the /dev/dsp* devices refer to.  Should /dev/dsp
> refer to the first card and /dev/dsp2 the second?  If so, I cannot
> configure the device with aumix, and mplayer indicates that /dev/dsp2 does
> not exist.

> Are there any configuration issues involved with trying to use two
> identical soundcards on the same system?

> Thanks for any advice.

No experience with 2 sound cards, but other dual carded (bad wording?)
setups have been encountered.
What in my case(s) solved the problem was to invoke a second driver, where
the installation included specifics for one of the cards only. In fact I
would suggest that you locate the initialization point in the startup
files and then duplicate the sequence setting up your sound card. Edit
from generic setup to only use specifics for each cards so that you don't
get caught by the system catching the one card for both drivers -
inconvenient, eh? (been there...)

HTH

Jan, OZ1DKE.