lkml.org 
[lkml]   [2008]   [Aug]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Subjectcpufreq regression, unable to set lower frequency
    From
    Date
    Hi LKML,

    I've upgraded my kernel few days earlier and suddenly my cpufreqd
    stopperd working. My configuration is this:
    AC adapter connected:
    set scaling_max_freq and scaling_min_freq to maximal available
    frequency
    AC adapter disconnected:
    set scaling_max_freq to maximal available, scaling_min_freq to minimal
    available.

    When I connect AC adapter, everything works fine but when I disconnect
    my adapter, everything remains on maximal frequency and in logs I can
    see:

    cpufreqd: cpufreqd_set_profile: Couldn't set profile "Powersave Low" set
    for cpu0

    After some tests I've traced problem to

    http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.25.y.git;a=commitdiff;h=53391fa20cab6df6b476a5a0ad6be653c9de0c46

    What do you think? Is this condition correct?

    # cd /sys/devices/system/cpu/cpu0/cpufreq/

    when AC adapter is connected, something like this should happen:
    # cat scaling_available_frequencies
    2167000 2000000 1833000 1667000 1500000 1333000 1000000
    # echo 2167000 > scaling_max_freq
    # echo 2167000 > scaling_min_freq

    when disconnected, something like this should:
    # echo 1000000 > scaling_max_freq
    -su: echo: write error: Invalid argument
    # echo 1000000 > scaling_min_freq

    after min is set, max can be lowered to. Before this patch, lowering max
    below min lead to lowering of min to the same value.

    I think that this whole condition must not be here at all. After
    removing this condition the kernel behaves like this:


    # cat scaling_min_freq scaling_max_freq
    2167000
    2167000
    # echo 1000000 > scaling_max_freq
    # cat scaling_min_freq scaling_max_freq
    1000000
    1000000
    # echo 2167000 > scaling_min_freq
    # cat scaling_min_freq scaling_max_freq
    1000000
    1000000
    # echo 2167000 > scaling_max_freq
    # echo 2167000 > scaling_min_freq
    # cat scaling_min_freq scaling_max_freq
    2167000
    2167000


    Which I think is not perfect but is better then current behavior. What
    do you think?

    --
    Martin Filip <bugtraq@smoula.net>
    jabber: nexus@smoula.net
    [unhandled content-type:application/pgp-signature]
    \
     
     \ /
      Last update: 2008-08-21 20:23    [W:0.031 / U:31.008 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site