A recent Ubuntu 12.04 update has resulted in a flood of kernel log messages like:
Jun 10 16:53:50 fringe kernel: [1083938.675908] delay: estimated 222, actual 1
Jun 10 16:53:53 fringe kernel: [1083941.451942] delay: estimated 89, actual 0
Jun 10 16:54:02 fringe kernel: [1083950.876085] delay: estimated 309, actual 1
Jun 10 16:54:12 fringe kernel: [1083961.212252] delay: estimated 266, actual 1
Jun 10 16:54:28 fringe kernel: [1083976.940540] delay: estimated 265, actual 0
Jun 10 16:54:31 fringe kernel: [1083979.444548] delay: estimated 177, actual 1
Jun 10 16:54:40 fringe kernel: [1083989.164726] delay: estimated 265, actual 1
Jun 10 16:54:48 fringe kernel: [1083997.216594] delay: estimated 354, actual 1
Jun 10 16:54:48 fringe kernel: [1083997.220835] delay: estimated 134, actual 1
Jun 10 16:54:55 fringe kernel: [1084003.572938] delay: estimated 222, actual 1
Jun 10 16:55:31 fringe kernel: [1084039.821516] delay: estimated 266, actual 1
Jun 10 16:55:33 fringe kernel: [1084041.717585] delay: estimated 89, actual 0
whenever a USB sound card is used. (Even just sitting idle with no playback. As long as the card is selected as the output device in Sound settings, it happens.)
Here's a link to a message from about a year ago where Pierre-Louis Bossart says he is the one who added this diagnostic message:
http://permalink.gmane.org/gmane.linux.alsa.devel/97011
Other references include:
https://bugzilla.redhat.com/show_bug.cgi?format=multiple&id=798844
http://www.gossamer-threads.com/lists/linux/kernel/1592033?do=post_view_threaded
There appears to be no functional impact or difference compared to how the sound card worked prior to the update. The warnings are either in error or warning of an insignificant condition.
The main problem with them is that they obscure important errors in the kernel logs, and waste disk space.
---
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
ApportVersion: 2.0.1-0ubuntu17.3
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: tmetro 2686 F.... pulseaudio
/dev/snd/pcmC0D0p: tmetro 2686 F...m pulseaudio
/dev/snd/controlC1: tmetro 2686 F.... pulseaudio
Card0.Amixer.info:
Card hw:0 'Intel'/'HDA Intel at 0xdb300000 irq 47'
Mixer name : 'Nvidia MCP77/78 HDMI'
Components : 'HDA:10ec0889,10250145,00100004 HDA:11c11040,10250145,00100200 HDA:10de0006,10de0101,00100000'
Controls : 38
Simple ctrls : 21
Card1.Amixer.info:
Card hw:1 'Set'/'C-Media USB Headphone Set at usb-0000:00:1d.0-2, full speed'
Mixer name : 'USB Mixer'
Components : 'USB0d8c:000c'
Controls : 5
Simple ctrls : 3
CheckboxSubmission: 4a2fa194ac4b2025b572a728c22df868
CheckboxSystem: ed86e29ffba809c116a39e33fa9fc45c
DistroRelease: Ubuntu 12.04
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 12.04.1 LTS "Precise Pangolin" - Release amd64 (20120823.1)
MarkForUpload: True
Package: alsa-driver (not installed)
ProcVersionSignature: Ubuntu 3.2.0-44.69-generic 3.2.44
Tags: precise
Uname: Linux 3.2.0-44-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip libvirtd lpadmin mythtv plugdev sambashare sudo
dmi.bios.date: 09/09/2008
dmi.bios.vendor: Acer
dmi.bios.version: V1.06
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: Aspire 8930
dmi.board.vendor: Acer
dmi.board.version: PSMBOU-1234567
dmi.chassis.type: 1
dmi.chassis.vendor: Acer
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnAcer:bvrV1.06:bd09/09/2008:svnAcer:pnAspire8930:pvrV1.06:rvnAcer:rnAspire8930:rvrPSMBOU-1234567:cvnAcer:ct1:cvrN/A:
dmi.product.name: Aspire 8930
dmi.product.version: V1.06
dmi.sys.vendor: Acer
Could you plesae run "apport-collect 1189661" so we can get some more information about your hardware.
Thanks.