Subject: Lots of crashing with audio?
To: None <>
From: Peter Seebach <>
List: current-users
Date: 05/31/2006 15:21:25
Synopsis:  Recent -current crashing LOTS when using audio.  Rock-solid without

More details:  I have a laptop which I've been using with NetBSD since 2002.
The audio is auich0, based on an Intel ICH3.  It has worked pretty well for a
long time, although up through sometime last year, the audio would be
accellerated after a sleep/wake cycle.  (It was precisely as though you were
playing 44kHz samples at 48kHz.)

On a recent road trip, the laptop crashed CONSTANTLY, but only when using
audio.  Symptoms include:
* When using auich, whole system gets into weird unstable states, eventually
* When using uaudio, crashing is somewhat rarer, but the system eventually
panics.  However, no intermediate unstable state.  Panics were almost always
in everything BUT the audio program.
* When using uaudio in single-user mode, system ran fine for several hours.

I hypothesize that something near the audio code is overrunning a buffer or
something similar.

The only thing I can think of that's weird is that my system is compiled
	COPTS?=-march=pentium4 -mfpmath=sse -msse2 -O2 -pipe
I assume this affects kernel builds too.

I'm guessing that the sse option is being applied to the kernel, and is
in some cases resulting in registers that the kernel doesn't think it needs
to save getting smashed.  But I don't know; anyone else seen anything similar,
or able to confirm such a theory?