[PlanetCCRMA] Problem with jack

Fernando Lopez-Lezcano nando at ccrma.Stanford.EDU
Thu Apr 3 08:54:47 PDT 2008

On Thu, 2008-04-03 at 06:16 -0700, Len wrote:
> Hi,
> I recently did a fresh install of Fedora 8 from a Unity Project re-spin.  
> It's installed on an AMD Athlon X2 with 2GB RAM, but I installed the 
> 32-bit (i386) OS.  I'm using an Echo Layla24 PCI card, which I have set 
> up in modules.conf as sound-card-0 (I disabled the onboard HDA Intel 
> sound chip in the BIOS).   I then installed the planet ccrma kernel 
> (kernel-rt- and my favorite sound applications.

Does all this happen in the standard Fedora kernel?

> In jack (Qjackctl), I have it set to use RT, 128 frames/period, 48000 
> sample rate, 2 periods/buffer, 8 input/8 output channels, etc.  I started 
> up echomixer (to control hardware levels on Layla 24), qjackctl, and 
> zynaddsubfx to try out a little midi and audio using an external keyboard 
> controller connected to Layla's MIDI IN port.  
> When jack starts, the message window says "Enhanced 3DNow! detected" and 
> "Using SSE2", but the status window (main qjackctl panel) has the "RT" 
> indicator light alternately flashing on, then off, then on, then off, ...   
> I don't remember seeing this behavior before.  Then after some time, jack 
> just shuts down. 

Sounds like missing interrupts or something like that. Does it happen
with all programs? Always?

> At one point, while playing a synth patch from zynaddsubfx 
> and multiple keys/fast passage, it just locked up with a very annoying 
> constant tone (incoming! take cover!).
> Just for reference, I tried installing Fedora 7 (stock as well as ccrma-rt) 
> on this hardware setup and had so many problems I decided to give F8 a try.  
> In F7, eth0 would mysteriously go down (IRQ released), the soundcard and 
> alsa would randomly disconnect (IRQ again?), etc.  

It sort of sounds like the kernel is having problems with your

Sorry to not have any more ideas. [I may not be so responsive to emails
in the near future, I going on a trip in a couple of hours...]

-- Fernando

> I'll try and get some more output from dmesg, /proc/asound/, etc that 
> might be of more assistance, but I wondered if anyone had seen the "RT" 
> indicator light going on and off like this in qjackctl?

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