Audio Stops, video speeds up

Please run "apport-collect -p alsa-base 502226" in a terminal, so we can get more information about your sound hardware.

 affects ubuntu/alsa-utils
 status incomplete

Architecture: i386
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: roberto 2216 F.... pulseaudio
Card0.Amixer.info:
 Card hw:0 'CMI8738'/'C-Media CMI8738 (model 37) at 0x1000, irq 16'
   Mixer name : 'CMedia PCI'
   Components : ''
   Controls : 43
   Simple ctrls : 23
DistroRelease: Ubuntu 9.10
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release i386 (20091028.5)
NonfreeKernelModules: nvidia
Package: alsa-base 1.0.20+dfsg-1ubuntu5
PackageArchitecture: all
ProcEnviron:
 SHELL=/bin/bash
 LANG=en_US.UTF-8
ProcVersionSignature: Ubuntu 2.6.31-17.54-generic
Uname: Linux 2.6.31-17-generic i686
UserGroups: adm admin audio cdrom dialout fax lpadmin netdev plugdev sambashare vboxusers video

Please reproduce this symptom using alsa- *driver* 1.0.22.1.

  On 01/11/2010 10:08 AM, Daniel T Chen wrote:
> Please reproduce this symptom using alsa- *driver* 1.0.22.1.
>
> ** Package changed: alsa-utils (Ubuntu) => linux (Ubuntu)
>
Daniel T Chen,

Attached is the error log after attempting to reproduce the error.

Xie Xie

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The following patch was submitted to fix this bug (and others; the hash is from sound-2.6.git):

commit 1c583063a5c769fe2ec604752e383972c69e6d9b
Author: Clemens Ladisch <email address hidden>
Date: Wed Mar 24 07:10:54 2010 +0100

    ALSA: cmipci: work around invalid PCM pointer

    When the CMI8738 FRAME2 register is read, the chip sometimes (probably
    when wrapping around) returns an invalid value that would be outside the
    programmed DMA buffer. This leads to an inconsistent PCM pointer that is
    likely to result in an underrun.

    To work around this, read the register multiple times until we get a
    valid value; the error state seems to be very short-lived.

    Signed-off-by: Clemens Ladisch <email address hidden>
    Reported-and-tested-by: Matija Nalis <email address hidden>
    Cc: <email address hidden>
    Signed-off-by: Takashi Iwai <email address hidden>

any chance to get this patch backported to the kernels in karmic and lucid? (problem is persistent with upgrade to lucid)

Bug #464442 may be related. At least the workaround in https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/464442/comments/11 worked to fix this bug for me.

This bug was filed against a series that is no longer supported and so is being marked as Won't Fix. If this issue still exists in a supported series, please file a new bug.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.