[PlanetCCRMA] Planet CCRMA and (new) Gadget Labs driver questions...

Fernando Lopez-Lezcano nando at ccrma.Stanford.EDU
Tue May 6 00:18:55 PDT 2008


On Mon, 2008-05-05 at 21:18 -0400, Mike Mazarick wrote:
> > > 2. What are the best applications to test out the linux driver
> > > after you fire up qjackctl
>  
> > I usually fire up hydrogen for quick tests and select one of the demo
> > songs.
> 
> More good stuff
>
> > > I’m inclined to believe most of the ‘pro’ level stuff
> > > used with Jack, and there is some internal discussion about making
> > the card ‘Jack’ only.
> > >
> > > What would be your best recommendation of the set of apps that should
> > > be used for testing?   
> 
> > 
> > For multiple outputs and inputs Ardour would seem like the most
> > complete testbed.
>
> Excellent suggestion.   Since this is currently viewed by Jack as a 
> single 8 channel interface per card, is it practical to get multiple 
> instances of Jack running (one per card) or is re-working the driver 
> such that it looks like one big card a better solution? (it would only 
> need one Jack instance, but you'd be bound by only having one set of 
> interrupts available).   We've having to work some 'black magic' because 
> there is no direct DMA on the card.  Best 'guestimate' would be to do what 
> is normally done with multiple Delta 1010s that are clocked together.  
> Unfortunately, none of us have multiple Delta 1010s to look at.

Trying to use several cards as one involves some alsa magic that I have
not tested myself although some people have reported success (you create
a "virtual" device that spans all cards). I think only recent versions
of jack can work with that. 

Jack cannot simultaneously use several cards at once. And you can't
really have several instances of jack running at the same time and
aggregate them into one. 

-- Fernando




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