[LAU] could not start jack - already registered problem

[Johannes Kroll]

On Wed, 24 Apr 2013 16:10:56 +0200
Hartmut Noack <zettberlin at linuxuse.de> wrote:

> Am 24.04.2013 15:51, schrieb Len Ovens:
> > 
> > On Wed, April 24, 2013 6:26 am, Hartmut Noack wrote:
> >> Hello,
> >>
> >> I run KXStudio on Ubuntu 12.10 on a Lenovo Ideapad with a MAudio Mobile
> >> Pre USB1 interface.
> >>
> >> Normaly all this works near perfection but there is a problem starting
> >> Jack:
> >>
> > 
> >> Tue Apr 23 09:58:52 2013: ERROR: cannot register object path
> >> "/org/freedesktop/ReserveDevice1/Audio2": A handler is already
> >> registered for /org/freedesktop/ReserveDevice1/Audio2
> >> Tue Apr 23 09:58:52 2013: ERROR: Failed to acquire device name : Audio2
> >> error : A handler is already registered for
> >> /org/freedesktop/ReserveDevice1/Audio2
> > 
> > Ok, so what application already has the audio port? Are you running an
> > audio or video player? Have you been using a web browser that was seeing a
> > video or just hit a page with video adds?
> > 
> > To put it another way, does this problem show up right after a fresh
> > login?
> 
> Exactly: after a fresh login.
> 
> > or only after having used the system for a while. What does your
> > desktop use for most of it's non-jack audio output?
> 
> Before I do anything else, I check if Jack is running. Browser, Skype
> and the like use Pulse Jack sink, so I let Cadence start pulse-jack
> after starting Jack.

The command "lsof /dev/snd/pcm*" should show a list of commands which
are using any sound cards. Try it the next time the problem shows up.