[9.10 regression] HDA power_save=10

Note: Please file separate bugs on this issue - do not mark them duplicates.

From: Daniel Chen <>
To: ubuntu-devel-discuss <email address hidden>,
       Ubuntu Devel <email address hidden>
Subject: Recent changes to ALSA for power saving
Date: Tue, 26 May 2009 23:18:17 +0200

Hi all,

Luke and I have just pushed a one-line change to 9.10's
/etc/modprobe.d/alsa-base.conf that enables HDA controllers to power
down their amps after ten idle seconds. This change anticipates the
larger power-savings objectives for 9.10.

We expect there will be regressions in the form of audible pops when
the AMPs power down (and/or up). If you experience this symptom in
9.10, please file a bug using "ubuntu-bug alsa-base". Be sure to
change the summary of the bug afterward to "[9.10 regression] HDA
power_save=10".

Thanks,
Dan

reported bus as suggested by this post on the mailing lists.

started rhythmbox, pushed "pause" and after ten seconds amps gives noise.

Also:
Prior to this change, during shutdown, amps gives noise when they power down.

ProblemType: Bug
Architecture: amd64
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: SB [HDA ATI SB], device 0: STAC92xx Analog [STAC92xx Analog]
   Subdevices: 2/2
   Subdevice #0: subdevice #0
   Subdevice #1: subdevice #1
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: taavikko 4248 f.... mixer_applet2
Card0.Amixer.info:
 Card hw:0 'SB'/'HDA ATI SB at 0xd2400000 irq 16'
   Mixer name : 'IDT 92HD71B7X'
   Components : 'HDA:111d76b2,103c3600,00100302'
   Controls : 33
   Simple ctrls : 20
Card1.Amixer.info:
 Card hw:1 'HDMI'/'HDA ATI HDMI at 0xd2310000 irq 19'
   Mixer name : 'ATI R6xx HDMI'
   Components : 'HDA:1002aa01,00aa0100,00100000'
   Controls : 4
   Simple ctrls : 1
Card1.Amixer.values:
 Simple mixer control 'IEC958',0
   Capabilities: pswitch pswitch-joined
   Playback channels: Mono
   Mono: Playback [on]
Date: Wed May 27 13:03:18 2009
DistroRelease: Ubuntu 9.10
Package: alsa-base 1.0.20+dfsg-1ubuntu4
PackageArchitecture: all
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.30-6.7-generic
SourcePackage: alsa-driver
Uname: Linux 2.6.30-6-generic x86_64