Re: snd-cmipci with Jack not working

[Takashi Iwai <tiwai@suse.de>]

At Thu, 30 Jan 2003 12:00:32 +0200,
Antti Boman wrote:
> 
> Takashi Iwai wrote:
> > At Thu, 30 Jan 2003 01:48:18 +0200,
> > Antti Boman wrote:
> >>>>
> >>>>- I have the lowlat patch installed in kernel, but using or not using it
> >>>> doesn't seem to change anything.
> >>> 
> >>>most likely the kernel scheduler is irrelevant.
> >>
> >>The only effect it had was locking the whole machine when using 
> >>playback/capture only.
> > 
> > do you mean with LL-patch?  or with preempt patch?
> 
> Andrew Morton's 
> (http://www.zip.com.au/~akpm/linux/schedlat.html#downloads) patch. Sorry 
> about the flaws in terminology, I'm kind of half-dumb with these. If 
> there are even difference with those ones, I have to check them out 
> tonight and tell you then.
 
basically LL-patch is safer...
anyway i recommed to use without LL-patch (or disabled via sysctl) as
the first tests.  otherwise we don't know which is the culprit.
as long as no heavy disk access, the normal scheduler should work
fine.


> >>>>- Using jackd with playback/capture only, it produces the following
> >>>> message:
> >>>>  jackd: pcm.c:5851: snd_pcm_mmap_commit: Assertion 'pcm' failed
> >>> 
> >>>that's weird.
> >>
> >>Yes, and as you most probably know, it refers to alsa-lib/src/pcm/pcm.c
> >  
> > if the above function is directly called from jack, then it should be
> > a bug of jack.  the error above says the passed argument is a null
> > pointer.
> 
> I know. But I don't know if it's directly called from jackd. I'll try 
> and ask more on jackit-devel or try to find things myself. May be 
> another dead-end, though.
 
you can run non-stripped jackd in the source tree before installation,
and run from gdb to trace at which point this happens.


> > ah, sorry, what do you mean "kernel real-time patches"?
> > preempt-patch?
> > 
> > then i don't know.  i don't use them together with 2.4 kernels.
> 
> Then again, even without enabling low latency (whatsoever) it doesn't 
> work. I'm just afraid this won't be solved. And I'm not afraid for 
> myself, just for the fact that 8738 is a highly used chip. Have you 
> tried running jackd with the one of yours?

yes.  no hang up with -R and/or -P options, so far.

	# jackd -v -R -d alsa -d hw -r 44100 -p 512 -n 2

	# jackd -v -R -d alsa -d hw -r 44100 -p 512 -n 2 -P


Takashi


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