Re: [Jack-Devel] ARM JACK2 probs

On 05/27/2013 07:07 PM, Dan MacDonald wrote:
> My poor Pandaboard had lay unused for months until recently when I decided
> I should try Debian Wheezy on it. I was pleased to discover it runs
> quicker, boots quicker, performs faster and is more stable than the Ubuntu
> 12.04 it ran previously - which is what I had hoped for. Wifi and gfx
> aren't working properly (or at at all, as the case with wifi) yet but
> that's a discussion for elsewhere.
> 
> Like anyone on the JACK mailing list, as soon as I saw the system was
> running well on the whole, it was time to see how well it runs JACK! I was
> well aware the Wheezy J2 package is a bit archaic now and I had noticed
> that some patches had been appled in git recently for ARM so I knew that
> compiling J2 from git was the way to go so thats what I did a few days back
> and I've since installed Cadence too to make running it easier.
> 
> I have a few USB audio devices but the first I tried with JACK on my
> Pandaboard was my Philips portable hifi. Running JACK @ 48000/1024/2, I can
> keep it running pretty much until I pull the plug without any xruns
> although there is a slight backround pop noise every second or so. Not so
> bad as to make casual listening impossible but regular and frequent enough
> to be a deal-breaker for doing any serious audio work. This device works
> well enough to make me believe J2 on ARM is nearly ready, hopefully!
> 
> Sadly, I've not has as much luck with my other 2 USB audio devices but I'm
> hoping the JACK devs can help me fix those. The one that I've had more
> success with is the Focusrite 2i4. I have tried various JACK settings but I
> get the same result - JACK starts and runs xrun-free for just over 3m
> (about 3m 9s) then the gain input LEDs start blinking in tandem (some sort
> of error code) and then I get a steady flow of xruns which I can only stop
> by pulling the USB plug. Here is a JACK log for my 2i4:
> 
> Mon May 27 16:30:48 2013: Saving settings to
> "/home/debian/.config/jack/conf.xml" ...
> Mon May 27 16:31:13 2013: Starting jack server...
> Mon May 27 16:31:14 2013: JACK server starting in realtime mode with
> priority 10
> Mon May 27 16:31:14 2013: Acquired audio card Audio2
> Mon May 27 16:31:14 2013: creating alsa driver ...
> hw:USB,0|hw:USB,0|1024|2|48000|0|0|hwmon|swmeter|-|32bit
> Mon May 27 16:31:14 2013: configuring for 48000Hz, period = 1024 frames
> (21.3 ms), buffer = 2 periods
> Mon May 27 16:31:14 2013: ALSA: final selected sample format for capture:
> 32bit integer little-endian
> Mon May 27 16:31:14 2013: ALSA: use 2 periods for capture
> Mon May 27 16:31:15 2013: ALSA: final selected sample format for playback:
> 32bit integer little-endian
> Mon May 27 16:31:15 2013: ALSA: use 2 periods for playback
> Mon May 27 16:31:16 2013: graph reorder: new port 'system:capture_1'
> Mon May 27 16:31:16 2013: New client 'system' with PID 0
> Mon May 27 16:31:16 2013: graph reorder: new port 'system:capture_2'
> Mon May 27 16:31:16 2013: graph reorder: new port 'system:playback_1'
> Mon May 27 16:31:16 2013: graph reorder: new port 'system:playback_2'
> Mon May 27 16:31:16 2013: graph reorder: new port 'system:playback_3'
> Mon May 27 16:31:16 2013: graph reorder: new port 'system:playback_4'
> Mon May 27 16:34:33 2013: Stopping jack server...
> Mon May 27 16:34:38 2013: ERROR: JackPosixProcessSync::LockedTimedWait
> error usec = 5000000 err = Connection timed out
> Mon May 27 16:34:38 2013: ERROR: JackEngine::ClientDeactivate wait error
> ref = 2 name = dbusapi
> Mon May 27 16:34:38 2013: ERROR: failed to deactivate dbusapi jack client.
> error is -1
> Mon May 27 16:34:38 2013: Client 'system' with PID 0 is out
> Mon May 27 16:34:39 2013: ERROR: JackPosixProcessSync::LockedTimedWait
> error usec = 1000000 err = Connection timed out
> Mon May 27 16:34:39 2013: ERROR: JackEngine::ClientCloseAux wait error ref
> = 2
> Mon May 27 16:34:57 2013: ERROR: ALSA: prepare error for playback on
> "hw:USB,0" (Protocol error)
> Mon May 27 16:34:57 2013: ERROR: JackAudioDriver::ProcessAsync: read error,
> stopping...
> 
> Of course, the 2i4 runs for much longer than 3m with no probs on my x86
> machines. I've got a 3rd USB audio device (Startech 7.1 - I forget the
> chipset) that works fine with JACK on my laptop but won't start JACK at all
> on my Pandaboard.
> 
> Thanks for your help!
> 

The issues you describe are likely not related to jack at all.

Please try to play a long song with alsa's "aplay". ie confirm it's not
a general USB or audio problem.

My first guess would be power: The 2i4 is USB bus powered. Can your
panda-board provide 500mA to the USB bus? Is the Phillips device also
bus-powered? In either case it could explain the behavior (slight
background noise, pops, unstable USB connection) that you're experiencing.

Also try running with 3 periods of playback latency (-n option). e.g.
  jackd -d alsa -p 1024 -n 3
that helps with many USB devices. Try different period-sizes as well.

Check the output of 'dmesg' when jack disconnects. And also watch
/proc/interrupts (does the audio-device share IRQ with other hardware?)


Some other hints which -- are likely unrelated at this stage but -- can
improve general jack performance (less x-runs at lower latencies) are
apt-get install rtirq (setup IRQ priorities prefer audio-devices)
and also try the Debian's rt-preemt realtime kernel...

so long,
robin

1369676727.16551_0.ltw:2,a <51A39BAD.6040006 at gareus dot org>