[linux-audio-user] USB-audio-card notches

[Christoph Eckert]

Hi,


it's easter time, so I play a bit with aeolus ;-) .

Anyway, I have a Dell Inspiron 8200 with a vanilla 2.6.10 
kernel. The only patch applied is the LSM-RT-patch.

The Inspiron offers a USB 1.1 port. A USB 2.0 hub is connected 
to it.

On the hub, there are currently two USB devices:

* A Midisport 8x8
* A Terratec Aureon 5.1 USB

On top of the card, I start JACK. I tried various settings, 
currently I use

/usr/bin/jackd -v -R -P5 -p16 -t2000 -dalsa -dplughw:2 -r48000 
-p256 -n3 -P

As soon as I play through JACK, I get notches, regardless if 
it was alsa modular synth, Aeolus or xmms. The log shows 
lines like the ones attached below.

So I stopped JACK and tried to use the device in ALSA only 
mode.

* xmms now plays fine on the device hw:2,0
* ams and aeolus produce a lot of xruns and I get no audio 
output using hw:2,0
* when starting ams as
ams --soundcard plughw:2,0 --rate 48000
I get a lot of xruns again and the sound is worse (more 
notches) as when running ams or Aeolus on top of JACK
* notches also appear as soon as I try to record audio input 
using qarecord connected to JACK
* when using plughw:2,0 and a samplerate of 48000 (44100 will 
not work) in the aeolusrc, I get proper output at least by 
Aeolus

I could need a helping hand by making the card working 
properly. Anyone an idea where I can put the screwdriver?

I did also have a look into the modinfo of snd-usb-audio, but 
I cannot detect a parameter to tell it, mybe, to use a 
samplerate of 48000 or similar settings:

modinfo snd-usb-audio
author:         Takashi Iwai <tiwai at suse.de>
description:    USB Audio
license:        GPL
parm:           index:Index value for the USB audio adapter.
parm:           id:ID string for the USB audio adapter.
parm:           enable:Enable USB audio adapter.
parm:           vid:Vendor ID for the USB audio device.
parm:           pid:Product ID for the USB audio device.
parm:           nrpacks:Max. number of packets per URB.
parm:           async_unlink:Use async unlink mode.
vermagic:       2.6.10ce SMP PENTIUMII 4KSTACKS gcc-3.3
depends:        snd-usb-lib,snd-pcm,snd


Every wee small hint (even RTFM ;-) is much appreciated.


BTW: Is this the right place, or should I post it to LAD?


 Best regards


    ce






JACK log:



client qjackctl-13201: start_fd=5, execution_order=0.
client aeolus: in subgraph after qjackctl-13201, 
execution_order=1.
client qjackctl-13201: wait_fd=18, execution_order=2.
client alsa_pcm: internal client, execution_order=3.
-- jack_rechain_graph()
23:10:59.394 Audio active patchbay scan...
load = 11.6229 max usecs: 636.000, spare = 4697.000
load = 11.3899 max usecs: 595.000, spare = 4738.000
load = 11.2547 max usecs: 593.000, spare = 4740.000
load = 11.5246 max usecs: 629.000, spare = 4704.000
load = 11.4345 max usecs: 605.000, spare = 4728.000
delay of 5962.000 usecs exceeds estimated spare time of 
4728.000; restart ...
23:11:05.205 XRUN callback (4).
load = 11.9895 max usecs: 669.000, spare = 4664.000
load = 12.4077 max usecs: 684.000, spare = 4649.000
load = 11.8479 max usecs: 602.000, spare = 4731.000
load = 11.7931 max usecs: 626.000, spare = 4707.000
load = 11.8219 max usecs: 632.000, spare = 4701.000
load = 11.9676 max usecs: 646.000, spare = 4687.000
load = 12.2936 max usecs: 673.000, spare = 4660.000
load = 12.2128 max usecs: 647.000, spare = 4686.000
delay of 6203.000 usecs exceeds estimated spare time of 
4686.000; restart ...
23:11:13.187 XRUN callback (5).
load = 12.2755 max usecs: 658.000, spare = 4675.000
load = 12.1850 max usecs: 645.000, spare = 4688.000
load = 12.3273 max usecs: 665.000, spare = 4668.000
load = 12.1640 max usecs: 640.000, spare = 4693.000
load = 11.9792 max usecs: 629.000, spare = 4704.000
load = 11.7837 max usecs: 618.000, spare = 4715.000
load = 11.8641 max usecs: 637.000, spare = 4696.000
load = 12.0824 max usecs: 656.000, spare = 4677.000
load = 12.1260 max usecs: 649.000, spare = 4684.000
load = 12.5321 max usecs: 690.000, spare = 4643.000
load = 12.4915 max usecs: 664.000, spare = 4669.000
load = 12.4899 max usecs: 666.000, spare = 4667.000
delay of 5249.000 usecs exceeds estimated spare time of 
4667.000; restart ...
23:11:25.203 XRUN callback (6).
load = 12.1516 max usecs: 630.000, spare = 4703.000
load = 11.8511 max usecs: 616.000, spare = 4717.000
load = 11.6165 max usecs: 607.000, spare = 4726.000
load = 11.6868 max usecs: 627.000, spare = 4706.000
load = 12.0031 max usecs: 657.000, spare = 4676.000