Re: USB Audio/Midiman - partial success

[Takashi Iwai <tiwai@suse.de>]

At Fri, 13 Sep 2002 14:59:40 +0900,
Patrick Shirkey wrote:
> 
> Takashi Iwai wrote:
> > At Tue, 10 Sep 2002 10:58:34 +0200 (METDST),
> > Clemens Ladisch wrote:
> > 
> >>>>The two PCM devices cannot be used at the same time anyway, so I think
> >>>>creating a quirk for interface 0 which says "ignore this" could work.
> >>>>Takashi, any comments?
> >>>
> >>>i think implementing a semaphore (or flag) for each endpoint would be
> >>>better, so that the driver can find generally double-endpoints
> >>>problem.
> >>
> >>I cannot imagine anybody else would be stupid enough to design a device
> >>with double endpoints. But then I didn't imagine Midiman would, either.
> >>Oh well, Murphy's Law ...  :-(
> > 
> > 
> > since many (at least plural :) devices have this problem, i changed
> > the usbaudio code slightly.  now a pcm stream is created per endpoint
> > instead of interface.
> > 
> > on this version, m-audio's device should have one (for duo) or two
> > (for quattro) pcm devices.
> > 
> > please let me know if any problems arise with this change.
> > 
> 
> FYI: I have found that using the quattro with jack is rock solid when 
> only accessing one of the pcms at a time at 48khz even as normal user.

oh, that's bad.  could you show the output of
/proc/asound/card0/stream* ?

> But switch to a higher sample rate and/or 4 channels(with root 
> priveledges and lowlatency scheduling on) and different things happen:
> 
> ----
>   jackd -v -d alsa -d quattro1 -r 96000 -p 192
> jackd 0.37.2
> Copyright 2001-2002 Paul Davis and others.
> jackd comes with ABSOLUTELY NO WARRANTY
> This is free software, and you are welcome to redistribute it
> under certain conditions; see the file COPYING for details
> 
> 10691 waiting for signals
> creating alsa driver ... quattro1|192|2|96000|swmon
> ALSA lib pcm_hw.c:398:(snd_pcm_hw_prepare) SNDRV_PCM_IOCTL_PREPARE 
> failed: Invalid argument
  ^^^^^^^^^^^^^^^^^^^^^^^^
hmm...

> ALSA: cannot set hardware parameters for capture
> ALSA: cannot configure capture channel
> cannot load driver module alsa
> jack main caught signal 15
> ----
> jackd -v -d alsa -d q4b -r 48000 -p 3072
> jackd 0.37.2

did you run jack with 48k immediately after setting 96k?
so, some old configuration is left and this makes the difference.
perhaps this is also the problem once you reported that the driver
works only after once capture runs.


ciao,

Takashi


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