Comment 0 for bug 519142

CPU speed is stuck at 800MHz, almost all of the time, doesn't matter if CPU is loaded or not.

I can see from utilities like powertop or the gnome cpu freq applet, that it changes to 2GHz in some moments, but without actual relation with cpu load. When I need the CPU speed for an intensive CPU task (e.g. most trivial watching a flash video, it would lag and cannot be played normally) I see that CPU load is at 98% all the time.. but CPU speed stays at 800MHz.

I can change the default ondemand governor to some other (via the gnome applet), but without any difference in cpu scaling. It just continues to jump to 2GHz for some seconds but as I said unrelated to load of system. I *cannot* set the speed to a fixed one, e.g. 2GHz or any of the others, neither with the applet nor with tools like cpufrequtils.

Problem is present with all kernels provided with ubuntu karmic - 2.6.31-14,-17,-19

I did a test with ubuntu hardy 8.04 and problem is not present, all is working fine. It was with kernel 2.6.24-26 and acpi_cpufreq is a module there it seems.

---

Some interesting (for me) observation that I made is while trying to use a custom 2.6.31-17 ubuntu kernel provided by linux-phc team, meant for undervolting the cpu (can be found on "https://launchpad.net/~linux-phc/+archive/ppa" (linux-phc.org) ):

1. I installed their kernel which is shipped with default acpi_cpufreq compiled as a module, which module is later supposed to be replaced by a custom module by linux-phc.org.

After installation/booting and *before* putting the custom module I noticed that the system is running with the ondemand governer and CPU scaling looked to work fine. E.g. the fastest test for me is to play some flash videos that I cannnot play with normal karmic install. All was working. Then I tried to set the speed to fixed one 2GHz via the gnome applet and I didn't succeed. Then it never worked any more, even after reboot, neither with ondemand governor nor with other governors or fixed speeds.

2. I replaced the acpi_cpufreq with the custom module and again it looked for some time that the ondemand governer was working fine. Until I tried to set a fixed speed via the gnome applet. Then again it all stopped working, reboots didn't change the status-quo.

I'm not very sure if these observations are correct, that's why I put them under line.

ProblemType: Bug
Architecture: i386
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: u 1547 F.... pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'ICH6'/'Intel ICH6 with AD1981B at irq 22'
   Mixer name : 'Analog Devices AD1981B'
   Components : 'AC97a:41445374'
   Controls : 26
   Simple ctrls : 18
Date: Tue Feb 9 05:33:02 2010
DistroRelease: Ubuntu 9.10
HibernationDevice: RESUME=UUID=24cfd17e-9154-4562-a039-00ab6d21a593
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release i386 (20091028.5)
MachineType: IBM 2668VYU
Package: linux-image-2.6.31-19-generic 2.6.31-19.56
PccardctlIdent:
 Socket 0:
   no product info available
PccardctlStatus:
 Socket 0:
   no card
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.31-19-generic root=UUID=a94c75fc-bc48-46db-b642-36d5f5d0bca9 ro splash quiet splash
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-19.56-generic
RelatedPackageVersions:
 linux-backports-modules-2.6.31-19-generic N/A
 linux-firmware 1.25
RfKill:
 0: phy0: Wireless LAN
  Soft blocked: no
  Hard blocked: no
SourcePackage: linux
Uname: Linux 2.6.31-19-generic i686
dmi.bios.date: 08/21/2006
dmi.bios.vendor: IBM
dmi.bios.version: 1YET65WW (1.29 )
dmi.board.name: 2668VYU
dmi.board.vendor: IBM
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: IBM
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnIBM:bvr1YET65WW(1.29):bd08/21/2006:svnIBM:pn2668VYU:pvrThinkPadT43:rvnIBM:rn2668VYU:rvrNotAvailable:cvnIBM:ct10:cvrNotAvailable:
dmi.product.name: 2668VYU
dmi.product.version: ThinkPad T43
dmi.sys.vendor: IBM