[PlanetCCRMA] jackd and two Delta1010 cards

Fernando Lopez-Lezcano nando@ccrma.Stanford.EDU
Tue Jul 4 12:00:09 2006


On Tue, 2006-07-04 at 12:26 +0000, Bob Wilkinson wrote:
> uname -r
> 2.6.12-0.21.rdt.rhfc4.ccrma
> 
> rpm -q -a|grep kernel-module-alsa
> kernel-module-alsa-2.6.12-0.21.rdt.rhfc4.ccrma-1.0.9b-1.rhfc4.ccrma

I see, that's the "original" stable kernel, very old by now. You may
want to try the so called "edge" kernels, there's a 2.6.16 derivative
available there. Then again, this may not solve the problem at all.
Maybe you could post your question in the jack-devel mailing list and
somebody would know more about compatible versions and this particular
problem. 

The edge kernels are in a separate repository, you have to enable it to
the get them. Check your /etc/apt/sources.list.d/planetccrma.list file,
edit it and make a copy of the line that says "planetcore" at the end
(that's the repository where the kernel stuff is stored). Change
"planetcore" in the copy to "planetedge". Save the file, "apt-get
update" and then "apt-get install planetccrma-core-edge" for the single
processor kernel and alsa modules. 

The edge kernel is patched with the latest (not any more) Ingo Molnar's
realtime preemption patch, it has the best low latency performance but
may not work well with all hardware combinations. If you keep the "edge"
repository in your file there is _another_ newer kernel/alsa you can try
- just install "apt-get install planetccrma-core", that should get you a
2.6.16 kernel with Ingo's patch  configured as DESKTOP_RT, not as good
realtime performance but more chance of better compatibility. 

-- Fernando


>  -------------- Original message ----------------------
> From: Fernando Lopez-Lezcano <nando@ccrma.Stanford.EDU>
> > On Mon, 2006-07-03 at 18:17 +0000, Bob Wilkinson wrote:
> > > Hopefully someone can help me on this.  I have installed Planet CCRMA 
> > > from an FC4 installation.  I am using two Delta1010 sound devices, and 
> > > am trying to get them to act as one big device.
> > > 
> > > I have searched the web, and found an .asoundrc file (I actually wrote 
> > > it to /etc/asound.conf) to create the "virtual" card (binding the two 
> > > cards together).  My asound.conf file looks like this:
> > > 
> > > pcm.multi_capture {
> > >         type multi
> > >         slaves.a.pcm hw:0
> > >         slaves.a.channels 12
> > >         slaves.b.pcm hw:1
> > >         slaves.b.channels 12
> > [MUNCH]
> > > 
> > > However, when I attempt to run JACK from a command line,
> > > 
> > > jackd -d alsa -C multi_capture -P multi_playback
> > > 
> > >  I get the error:
> > > 
> > > ALSA: mmap-based access is not possible for the capture stream of this audio 
> > interface
> > > ALSA: cannot configure capture channel
> > > 
> > > I have tried just starting jack for multi_playback only - same error, just 
> > replaced 
> > > with "playback".
> > > 
> > > Unfortunately, I'm a complete newbie, and now have less than a week before 
> > > my company expects this thing to be up and running flawlessly.
> > > 
> > > Can anybody help?  What am I missing?
> > 
> > Which kernel/alsa are you running? Run:
> >   uname -r
> > to see which kernel you are booting. There should be a matching
> > kernel-module-alsa package for it ("rpm -q -a|grep kernel-module-alsa")
> > 
> > I seem to remember that alsa had problems with this type of stuff. I
> > also seem to remember a post about this being solved but I don't
> > remember on which version. 
> >