[ltp] Frequency scaling not working in /sys in T41

[Miguel Hermanns]

Hi,

I'm trying to use powernowd on my T41, but for the moment without 
success. I have reviewed the messages of the mailinglist from the last 4 
months without finding a solution to my problem. My system is a T41 
(centrino) with debian sarge, kernel 2.6.6 (debian standard one) and the 
following modules loaded:

Module                  Size  Used by
snd_mixer_oss          20384  0
ipv6                  271296  8
ds                     18788  4
lp                     11524  0
thermal                12816  0
fan                     4204  0
button                  6712  0
ac                      5036  0
battery                 9580  0
ipw2100               159048  0
firmware_class         10496  1 ipw2100
hostap                112136  1 ipw2100
yenta_socket           21600  0
pcmcia_core            68228  2 ds,yenta_socket
snd_intel8x0m          20100  0
snd_intel8x0           35880  0
snd_ac97_codec         66052  2 snd_intel8x0m,snd_intel8x0
snd_pcm               102240  2 snd_intel8x0m,snd_intel8x0
snd_timer              27044  1 snd_pcm
snd_page_alloc         11716  3 snd_intel8x0m,snd_intel8x0,snd_pcm
gameport                5120  1 snd_intel8x0
snd_mpu401_uart         8608  1 snd_intel8x0
snd_rawmidi            25472  1 snd_mpu401_uart
snd_seq_device          8456  1 snd_rawmidi
snd                    57124  9 
snd_mixer_oss,snd_intel8x0m,snd_intel8x0,snd_ac97_codec,snd_pcm,snd_timer,snd_mpu401_uart,snd_rawmidi,snd_seq_device
hw_random               5844  0
uhci_hcd               32528  0
shpchp                103180  0
pciehp                103180  0
pci_hotplug            37468  2 shpchp,pciehp
intel_agp              18780  1
intel_mch_agp          10800  0
agpgart                34892  2 intel_agp,intel_mch_agp
parport_pc             35840  1
parport                43272  2 lp,parport_pc
irtty_sir               9984  0
sir_dev                20316  1 irtty_sir
irda                  210112  2 irtty_sir,sir_dev
pcspkr                  3852  0
ehci_hcd               31012  0
usbcore               110716  4 uhci_hcd,ehci_hcd
i810_audio             35572  1
ac97_codec             19212  1 i810_audio
soundcore              10880  3 snd,i810_audio
e1000                  85604  0
capability              4324  0
commoncap               7520  1 capability
cpufreq_userspace       7296  2
proc_intf               4160  0
tsdev                   7552  0
mousedev               10328  2
evdev                   9760  0
speedstep_centrino      7700  0
freq_table              4576  1 speedstep_centrino
processor              17888  2 thermal,speedstep_centrino
radeon                118224  0
psmouse                20712  0
ide_cd                 43748  0
cdrom                  40800  1 ide_cd
rtc                    14184  0
vfat                   15456  0
fat                    47840  1 vfat
ext2                   75080  2
ext3                  128648  0
jbd                    70040  1 ext3
mbcache                10340  2 ext2,ext3
ide_disk               20288  4
ide_generic             1632  0
piix                   14080  1
ide_core              152216  4 ide_cd,ide_disk,ide_generic,piix
unix                   31024  498
fbcon                  30628  71
font                    8544  1 fbcon
vesafb                  6196  1
cfbcopyarea             4064  1 vesafb
cfbimgblt               3264  1 vesafb
cfbfillrect             4000  1 vesafb

When not using any freq daemon, I can control the frequencies of the 
system by doing

echo 7 > /proc/acpi/processor/CPU/throttling

and the system gets slow after that. But looking at /proc/cpuinfo I 
always get

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 9
model name      : Intel(R) Pentium(R) M processor 1400MHz
stepping        : 5
cpu MHz         : 1395.402
cache size      : 1024 KB
...

so the cpuinfo is not being updated, but at least the system responds 
slower, so I guess the throttling works. Now I switch to the options in 
/sys. The settings of the files in /sys/devices/system/cpu/cpu0/cpufreq/ 
are:

cpuinfo_max_freq:
1400000
cpuinfo_min_freq:
600000
scaling_available_frequencies:
1400000 1200000 1000000 800000 600000
scaling_available_governors:
userspace performance
scaling_driver:
centrino
scaling_governor:
userspace
scaling_max_freq:
1400000
scaling_min_freq:
600000
scaling_setspeed:
1400000

I have tried to set a frequency in scaling_setspeed with the command:

echo "600000" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed

and the content of the file scaling_setspeed is changed, but the systems 
speed is still the same (at least the feeling, since the cpuinfo does 
not change). I guess this is a wrong behaviour, since the options in 
/sys should also work, or? I have also checked the bugzilla page of the 
kernel, but I have not found any bug directly related to my problem.

Does somebody have any idea?

Thanks in advance,

Miguel