New subject: [Jackit-devel] Re: [linux-audio-user] jackd and usb 1.1 audio on i386 non-functional

3 Mar 2006

----- Lee Revell &lt;rlrevell(a)joe-job.com&gt; wrote:
...
  On Fri, 2006-03-03 at 23:09 +0200, Sampo Savolainen
wrote:
  On Fri, 2006-03-03 at 13:18 -0500, Lee Revell
wrote:
 > > So, instead of interpreting them to users the software should  say:
"learn C
  > > headers and read errno.h?". Gah. 
 > > 
 > > Good software tells the users what's really wrong and directs  the
user in
  > > how to fix the issue. This leads to
happier users and less  repeated "why
  > > doesn't this work" questions
on mailing lists, irc, personal  email, etc.

 We don't KNOW what's wrong beyond "not enough bandwidth".  
 "Problems with jackd using your soundcard. Specifically 'Not enough
 bandwidth'. If you are using an USB soundcard, this probably means  that
  you are running the soundcard with either a wrong
buffer size or a  wrong
  amount of periods. Try running jackd with -r
3"

 We don't? I think we do know more. :)

 "Or maybe you have enabled CONFIG_USB_BANDWIDTH.  Or your kernel is
 buggy.  Or your device is connected through a hub.  The solution may
 depend on which host controller driver you are using..." 
Crap. Those are a lot of variables. Perhaps a troubleshooting guide for USB interfaces?
The alsa wiki is a total mess on this subject. I don't know enough about the issue to
filter out what's true and what's luck but I would like to edit that document to
be more conclusive. Here's where I'm at with my setup:

1) CONFIG_USB_BANDWIDTH is not configured
2) Buggy kernel? How do I determine that? the initial test was 2.6.12.2, I am installing
2.6.15.5 tonight.
3) Device is not connected through a hub
4) the host controller is usb-uhci for controller 1, 2 and 3 then ehci-hcd for a fourth
5) I have not yet tried running jackd with -r 3. I did read that periods with an odd
number are deprecated but I did not understand the reason.

Anything other options I might have left out?

-lee

Re: [Jackit-devel] Re: [linux-audio-user] jackd and usb 1.1 audio on i386 non-functional