[LAU] JACK hanging upon slight USB power glitch

Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]
To: Linux Audio User <linux-audio-user@...>
Date: Monday, October 14, 2013 - 3:04 am

Sorry if this is an obvious question, but I'm short of time today and
really tired of Google searching.

I'm running:

Linux dlm-A6200 3.2.0-54-lowlatency #56-Ubuntu SMP PREEMPT Thu Sep 19
17:22:47 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

I have jack 2 connected via ALSA to an M-Audio Fast Track Pro.

If there is any slight glitch in the USB power -- for instance, in a
performance space where the sound engineer might need to plug/unplug cables
frequently -- jackd spins out of control on one CPU and often locks up the
user interface, forcing a hard shutdown and reboot. If I'm very lucky, I
can get into the terminal, find jack's PID and kill it, but when the mouse
and keyboard stop responding, there's nothing I can do reach for the power

This occurs less frequently in 12.04 than it did when I started with 10.04,
but when it does happen (as it did just now), it really, really ticks me

I think there must be some automated way for the system to recognize that
jack is out of control and kill it. [1] notes:

-t, --timeout int
Set client timeout limit in milliseconds. The default is
msec. In realtime mode the client timeout must be smaller
the watchdog timeout (5000 msec).

Interesting... "watchdog timeout"... but I have never seen any effect from
the watchdog mentioned here. Jack just keeps locking up the system for way
longer than 5 seconds.

I'm happy to provide more info if you can tell me what commands to run.
Normally I would research it myself, but I'm just not in the mood today. If
there's already good documentation on this, great, but... too many pages to
read and I have no idea which is the best one.


[1] http://manpages.ubuntu.com/manpages/precise/man1/jackd.1.html
Linux-audio-user mailing list

Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]

Messages in current thread:
[LAU] JACK hanging upon slight USB power glitch, James Harkins, (Mon Oct 14, 3:04 am)
Re: [LAU] JACK hanging upon slight USB power glitch, Jeremy Jongepier, (Mon Oct 14, 7:33 am)
Re: [LAU] JACK hanging upon slight USB power glitch, Paul Davis, (Mon Oct 14, 1:14 pm)