Re: Looping sound output from pcm

On Mon, 22 Dec 2003, Scott Long wrote:

> Robert Watson wrote:
> > I ran aim after a recent kernel update, and had a rather odd problem.  I
> > got an instant message from someone which resulted in a "ding" from aim. 
> > However, the ding never stopped dinging -- the sample repeated over and
> > over again, and continues as I type.  Even after the aim process exited. 
> > Sending additional sound output didn't make it go away either.  KDE/arts,
> > etc, don't seem to be involved in the problem, so it really seems like the
> > kernel is looping the sample.  When I try to unload pcm, I get: 
> > 
> > pcm0: unregister: channel pcm0:play:2 busy (pid 965)
> > 
> > And there's no pid 965.
> > 
> > paprika# cat /dev/sndstat 
> > FreeBSD Audio Driver (newpcm)
> > Installed devices:
> > pcm0: <ESS Technology Maestro3> at io 0xd800 irq 5 (4p/1r/0v channels duplex default)
> > 
> > Any suggestions welcome; in the mean time, I'll just listen to it ding
> > away ad naueseum. 
> > 
> > Robert N M Watson             FreeBSD Core Team, TrustedBSD Projects
> > robert_at_fledge.watson.org      Senior Research Scientist, McAfee Research
> > 
> 
> As was pointed out, this is probably an interrupt problem.  The sound
> hardware should have interrupted the driver to say that it was almost
> done playing what was in the _ring_ buffer, and the driver should have
> responded by either filling the buffer with new data, or turning off the
> hardware.  Instead, the hardware just kept on doing what it was designed
> to do: keep on playing through the ring buffer.  The same thing would
> have happened if the OS had crashed while a sample was playing.
> 
> The maestro3 driver is growing more stale over time.  I no longer have
> any hardware to deal with it though.  If anyone knows where I can get
> an Maestro3 or Allegro-1 PCI card, I'll gladly buy it and fix start
> working on the driver again.

If you can get your hands on some not-so-old Dell
laptops.  My Lattitude C400 at work has a Maestro3.