[linux-audio-user] JACK and ALSA can't use Delta 44, but OSS emulation through ALSA can

[Alan Taylor]

I'm having an issue getting sound out of my Delta 44.  As root I can use
JACK in RT mode to play to both my on-board soundcard and my Delta 44.
As a user in the audio group, I can use JACK in RT mode to play to my
on-board soundcard, but not my Delta 44.

So, I'm confident that realtime-lsm is working properly, and that my
ALSA config is fine for my on-board soundcard.  The only way I can get
sound out of my Delta 44 is to have root run JACK or have a user in the
audio group use OSS mode.

If I use an application like XMMS, I cannot use the ALSA driver directly
to play on the Delta 44 as root or a user.  I have to use either JACK as
root or OSS as a user.  It seems like it may be an ALSA issue, but I'm
at a loss to figure out why.  I've tried various .asoundrc configs, but
to no avail.  Gettting rid of a .asoundrc altogether yeilds the same
result.  I've tried turning off OSS emulation by not loading the
modules, but it makes no difference.

I'm using the Gentoo kernel 2.6.11-gentoo-r6 with realtime-lsm 0.8.5-r1.
Alsa is not built into the kernel.  Here's some more info:


# cat /proc/asound/version
Advanced Linux Sound Architecture Driver Version 1.0.8.
Compiled on Apr 15 2005 for kernel 2.6.11-gentoo-r6.


# cat /proc/asound/cards  
0 [M44            ]: ICE1712 - M Audio Delta 44
                     M Audio Delta 44 at 0xa400, irq 5
1 [nForce2        ]: NFORCE - NVidia nForce2
                     NVidia nForce2 with ALC650F at 0xe9080000, irq 9


When I start JACK through qjackctl, I get the following:

22:16:43.707 Patchbay deactivated.
22:16:43.726 Statistics reset.
22:16:43.738 MIDI connection graph change.
22:17:00.735 JACK is starting...
22:17:00.735 /usr/bin/jackd -R -dalsa -dhw:0 -r48000 -p1024 -n2 -i2 -o2
22:17:00.742 JACK was started with PID=19234 (0x4b22).
jackd 0.99.0
Copyright 2001-2003 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
loading driver ..
apparent rate = 48000
creating alsa driver ... hw:0|hw:0|1024|2|48000|2|2|nomon|swmeter|-|
32bit
control device hw:0
configuring for 48000Hz, period = 1024 frames, buffer = 2 periods
ALSA: cannot set channel count to 2 for capture
ALSA: cannot configure capture channel
cannot load driver module alsa
22:17:00.753 JACK was stopped successfully.
22:17:02.829 Could not connect to JACK server as client.

The error seems to point to the channel count, but whether I specify 2
or the proper number, which is 4, it makes no difference.  Permissions
and ownership:group in /dev/sound and /dev/snd appear to be fine.

Any suggestions would be greatly appreciated.  I can go on with life
running JACK and Ardour as root, but I'd really rather not.  Previously
installed instances of Gentoo I've pointed all applications to JACK
running as a user and everything is happy.  This install has me
scratching my head.


Alan