Ondemand governor never scales down when overclocking

[garga_mel]

Hi all,
I have tried to overclock my RPI2 running raspbian wheezy using the following settings in /boot/config.txt

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arm_freq=1000                                                                                       
core_freq=400
sdram_freq=450
over_voltage=2
gpu_mem=64
initial_turbo=30

This seems to improve the overall speed. However my pi2 never seems to scale down to 600 Mhz even when idle.
This is the output of cpufreq-info

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current CPU frequency is 1000 MHz.
cpufreq stats: 600 MHz:0.00%, 1000 MHz:100.00%

What am I missing ?

Thanks

[JimmyN]

Using "initial_turbo=30" in config.txt just sets turbo for initial boot, in this case for 30 seconds or until cpufreq sets a frequency, whichever occurs first.

You need to change the threshold for the ondemand governor, which is located at

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/sys/devices/system/cpu/cpufreq/ondemand/up_threshold

I usually set mine at "50", I think the default is somewhere around "90" IIRC, and I typically get something like this from "cpufreq-info"

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  current CPU frequency is 700 MHz.
  cpufreq stats: 700 MHz:97.62%, 900 MHz:2.38%  (2081)

[garga_mel]

I had "95" as an up_threshold value :

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cat /sys/devices/system/cpu/cpufreq/ondemand/up_threshold
95

I tried to change the value to "50" but it did not change anything

My CPU is stuck at 1000 Mhz instead of going back to 600 Mhz.

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cpufreq stats: 600 MHz:0.00%, 1000 MHz:100.00%

I'm am getting even more puzzeled here : I did not set arm_freq_min=600 and it appears that the default value is 700 mhz.

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sudo vcgencmd get_config arm_freq_min
arm_freq_min=0

[garga_mel]

Thanks for the help I have made some progress and using a fresh raspbian installation that the issue starts when I install the cpufrequtils package.

If I manually set the cpufreq min it seems to work fine :

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sudo cpufreq-set --min 800
[...]
cpufreq-info
[...]
current CPU frequency is 1000 MHz.
cpufreq stats: 600 MHz:97.55%, 1000 MHz:2.45%  (8)

But I am still stuck at the 600 Mhz instead of 800 Mhz

Are the cpufreqd and cpufrequtils required for an overclock of the pi 2 ?