Recently, while watching movies in VLC, after about 45 to 60 minutes sometimes ALSA will crash. The symptoms are:
1) Audio suddenly stops playing.
2) After a few seconds, video freezes.
3) System enters a tight loop, appearing to be almost completely frozen - mouse cursor will not move, SSH clients stop responding (but remain connected).
4) After a few seconds, there is heavy disk activity. The system may then start to gradually respond to keypresses (and SSH clients eventually update), but runs extremely slowly.
The system continues to lag severely (any input takes several seconds to register, screen refreshes only once every few seconds) until pressing Alt+SysRq+K to kill the X session and all processes under it and log in again. Even this takes quite a while to execute. Once the session terminates and GDM appears again, the system once again runs normally and audio resumes working.
At some point during this ordeal, a number of messages are written to syslog (see attachment).
ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: alsa-base 1.0.23+dfsg-1ubuntu4
ProcVersionSignature: Ubuntu 2.6.35-28.50-generic 2.6.35.11
Uname: Linux 2.6.35-28-generic i686
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
Architecture: i386
Card0.Amixer.info:
Card hw:0 'V8237'/'VIA 8237 with ALC655 at 0xc000, irq 22'
Mixer name : 'Realtek ALC655 rev 0'
Components : 'AC97a:414c4760'
Controls : 48
Simple ctrls : 29
Card1.Amixer.info:
Card hw:1 'J'/'A4 TECH A4 TECH USB2.0 PC Camera J at usb-0000:00:10.4-3.1.1, high speed'
Mixer name : 'USB Mixer'
Components : 'USB0ac8:c40a'
Controls : 3
Simple ctrls : 2
Date: Sun Apr 3 22:54:31 2011
InstallationMedia: Xubuntu 10.10 "Maverick Meerkat" - Release i386 (20101007)
PackageArchitecture: all
ProcEnviron:
PATH=(custom, no user)
LANG=en_CA.utf8
SHELL=/bin/bash
SelectedCard: 0 V8237 VIA8237 - VIA 8237
SourcePackage: alsa-driver
Symptom: audio
Title: [VIA8237 - VIA 8237] Playback problem
dmi.bios.date: 07/26/2005
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 080011
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: MS-7032
dmi.board.vendor: MSI
dmi.board.version: 1.0
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: To Be Filled By O.E.M.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr080011:bd07/26/2005:svnMSI:pnMS-7032:pvr1.0:rvnMSI:rnMS-7032:rvr1.0:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.name: MS-7032
dmi.product.version: 1.0
dmi.sys.vendor: MSI
Should also note that a similar problem had been occurring with a different sound card (different symptoms but same "returned a value that is exceptionally large" message) several months ago. Switching to the card I use now solved that problem and sound has been working fine until it crashed a few days ago and again today, both while playing video in VLC.