[Bug 9708] New: powersave governor does not work when power cable gets plugged in

[Bug 9708] New: powersave governor does not work when power cable gets plugged in

[bugme-daemon]

http://bugzilla.kernel.org/show_bug.cgi?id=9708

           Summary: powersave governor does not work when power cable gets
                    plugged in
           Product: Power Management
           Version: 2.5
     KernelVersion: 2.6.24-rc6-default
          Platform: All
        OS/Version: Linux
              Tree: Mainline
            Status: NEW
          Severity: normal
          Priority: P1
         Component: cpufreq
        AssignedTo: cpufreq@www.linux.org.uk
        ReportedBy: deller@gmx.de


Hardware Environment:
HP NC6000 Laptop (Intel(R) Pentium(R) M processor 1.60GHz)

Problem Description:
cpufreq powermanagemnt does work pretty ok.
Nevertheless, I face a problem when I suddenly plug in the power cable.

Machine has no load, nevertheless I then can see (even minutes after I plugged
in the power cable):

[root@halden cpufreq]# uptime &&  grep ""
/sys/devices/system/cpu/cpu0/cpufreq/*

 21:57:23 up  1:04,  3 users,  load average: 0.09, 0.08, 0.09

/sys/devices/system/cpu/cpu0/cpufreq/affected_cpus:0
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq:1600000
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq:1600000
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq:600000
/sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies:1600000
1400000 1200000 1000000 800000 600000
/sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors:conservative
ondemand powersave userspace performance
/sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq:1600000
/sys/devices/system/cpu/cpu0/cpufreq/scaling_driver:acpi-cpufreq
/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor:powersave
/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq:1600000
/sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq:600000

As you can see, the CPU can scale between 600 MHz and 1600 MHz.
The governour is "powersave", but scaling_cur_freq constantly stays at 1600
MHz. In principle the powersave governour should now scale it down to 600 MHz,
but it does not.

Interestingly, when I then switch the scaling governor to "performance" (or any
other value than powersave) and then directly back to powersave, it then
suddenly does work as designed and scales the CPU down to 600MHz. It seems the
short change in the governor triggers start of the scale-down.


-- 
Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.

[Bug 9708] powersave governor does not scale down when power gets connected

[bugme-daemon]

http://bugzilla.kernel.org/show_bug.cgi?id=9708


deller@gmx.de changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|powersave governor does not |powersave governor does not
                   |work when power cable gets  |scale down when power gets
                   |plugged in                  |connected




-- 
Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.

[Bug 9708] powersave governor does not scale down when power gets connected

[bugme-daemon]

http://bugzilla.kernel.org/show_bug.cgi?id=9708





------- Comment #1 from trenn@suse.de  2008-01-08 03:46 -------
Do you use the latest BIOS for this machine?
Do you have a related option in BIOS configuration set, like:
"Full performance on AC"
or similar?

Do you see ACPI PACKAGE_LIMIT errors in dmesg? (-> then this is probably
related to: http://bugzilla.kernel.org/show_bug.cgi?id=9558)


-- 
Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.

[Bug 9708] powersave governor does not scale down when power gets connected

[bugme-daemon]

http://bugzilla.kernel.org/show_bug.cgi?id=9708





------- Comment #2 from deller@gmx.de  2008-01-08 10:51 -------
Yes, I'm using the latest BIOS.

In the BIOS there is no specific Performance/ACPI changes possibile. The only
option I found was something like "Use Intel SpeedStep Technology" with Yes,
No, Automatic. I choosed Automatic.

I don't see any ACPI error messages in dmesg. The problem in
http://bugzilla.kernel.org/show_bug.cgi?id=9558 does not seem related to my
bug.

Any other ideas or any other information needed?


-- 
Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.

[Bug 9708] powersave governor does not scale down when power gets connected

[bugme-daemon]

http://bugzilla.kernel.org/show_bug.cgi?id=9708





------- Comment #3 from trenn@suse.de  2008-01-09 01:41 -------
I expect you are seeing the same bug:
https://bugzilla.novell.com/show_bug.cgi?id=334378

Compiling the kernel with CONFIG_CPU_FREQ_DEBUG=y and boot with cpufreq.debug=7
parameter. Also add ACPI_DEBUG=y and add acpi.debug_level=0x1f boot parameter
(maybe an ACPI event happens at a certain time that leads to this condition?).
It may also help if you do the performance and back to powersave governor
switches and mark the positions in dmesg logs when those have been issued.


-- 
Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.

[Bug 9708] powersave governor does not scale down when power gets connected

[bugme-daemon]

http://bugzilla.kernel.org/show_bug.cgi?id=9708





------- Comment #4 from deller@gmx.de  2008-01-09 12:40 -------
Created an attachment (id=14385)
 --> (http://bugzilla.kernel.org/attachment.cgi?id=14385&action=view)
Full syslog from bootup to shutdown. Problem happened shortly before timestamp
"Jan  9 21:14:59"

Good news! Attached is the full syslog from startup of system to shutdown with
ACPI debug enabled.
If you watch out for the "MARKER:" flags, you'll see what I just started to do,
or what I just found. The real problem happens between timestamp 21:14:35 and
21:14:59 
Hope that helps to find the bug.

PS: It seems cpufreq debugging is not visible. maybe the boot option you
mentioned was wrong? (I'll check if necessary).


-- 
Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.

[Bug 9708] powersave governor does not scale down when power gets connected

[bugme-daemon]

http://bugzilla.kernel.org/show_bug.cgi?id=9708





------- Comment #5 from deller@gmx.de  2008-01-09 12:47 -------
Hi Thomas,
yep, this bug report here is exactly the same symptom/problem as in Novell's
bugzilla https://bugzilla.novell.com/show_bug.cgi?id=334378.

Differences are:
- different Laptops (HP & Dell)
- different Linux kernel versions (incl. mainline 2.6.24 which I run)
- different distributions (Fedora & SUSE)
-> IMHO clearly a Linux kernel problem in all kernels (2.6.22 -> 2.6.24).


-- 
Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.

[Bug 9708] powersave governor does not scale down when power gets connected

[bugme-daemon]

http://bugzilla.kernel.org/show_bug.cgi?id=9708


trenn@suse.de changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |stevenm@umd.edu




------- Comment #6 from trenn@suse.de  2008-01-22 16:43 -------
*** Bug 9151 has been marked as a duplicate of this bug. ***


-- 
Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.

[Bug 9708] powersave governor does not scale down when power gets connected

[bugme-daemon]

http://bugzilla.kernel.org/show_bug.cgi?id=9708


trenn@suse.de changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|cpufreq@www.linux.org.uk    |trenn@suse.de
             Status|NEW                         |ASSIGNED




------- Comment #7 from trenn@suse.de  2008-02-01 05:32 -------
> PS: It seems cpufreq debugging is not visible. maybe the boot option you
> mentioned was wrong? (I'll check if necessary).
The parameter should be right. Are you sure you compiled CPU_FREQ_DEBUG into
the kernel? You can double check with:
zcat /proc/config.gz|less
Maybe it is wrong, you should find help with google...

Can you also add a debug patch (which hopefully will be mainline soon...,
Dave?), I posted it to the cpufreq list a while ago:
http://article.gmane.org/gmane.linux.kernel.cpufreq/5642

Also add another patch (I will attach it)


-- 
Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.
You are the assignee for the bug, or are watching the assignee.