Author Topic: How To Change Cpu Freq In Debian Eabi?  (Read 3852 times)

ecc_hy

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How To Change Cpu Freq In Debian Eabi?
« on: January 29, 2008, 01:51:40 am »
There is only cpuoverclock.py to change the cpu freq. It is not enough and caused screen flicker.

1. As yonggun's cpufreq kernel, it support cpufreq interface and use cpufreqd to change cpu freq according to cpu usuage.

2. PXA support speedstep. It means the cpu freq can be changed only step by step. It may cause hardware problem if we change cpu freq too much. The problem has been found when I developed mb-applet-powerctrl.

3. Lower cpu freq has no problem when suspend or resume in pdaxrom. But in eabi, it cause white screen.
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2or0

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How To Change Cpu Freq In Debian Eabi?
« Reply #1 on: January 29, 2008, 10:18:53 am »
Quote from: ecc_hy
There is only cpuoverclock.py to change the cpu freq. It is not enough and caused screen flicker.

1. As yonggun's cpufreq kernel, it support cpufreq interface and use cpufreqd to change cpu freq according to cpu usuage.

2. PXA support speedstep. It means the cpu freq can be changed only step by step. It may cause hardware problem if we change cpu freq too much. The problem has been found when I developed mb-applet-powerctrl.

3. Lower cpu freq has no problem when suspend or resume in pdaxrom. But in eabi, it cause white screen.

You can use the command 'dvfm' to change the cpufreq.
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ecc_hy

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How To Change Cpu Freq In Debian Eabi?
« Reply #2 on: January 31, 2008, 10:29:11 pm »
I have test dvfm and cpuoverclock.py in my c1000 and kernel 2.6.22.9-yonggun.
After all, my c1000 is working properly on the default cpu frequence clock 416MHz.

When down frequence, the X cursor is freeze, keyboard and display is ok.
When up frequence, the console always display the message like "XXX can not battery status".

I have checked the dvfm in pdaxrom forum. the dvfm only change the voltage of the cpu called CCCR, but not change VCORE. As kernel 2.6, the file called "/sys/devices/system/cpu/cpu0/scaling_setspeed" should be work, but it is not exist in my c1000.
« Last Edit: January 31, 2008, 10:54:56 pm by ecc_hy »
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ecc_hy

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How To Change Cpu Freq In Debian Eabi?
« Reply #3 on: January 31, 2008, 11:03:58 pm »
cd /sys/devices/system/cpu/cpu0/
echo "userspace" > scaling_governor
echo "N" > scaling_setspeed
N can be 104000, 208000, 312000, 416000, 520000, 624000, or may be other freq in "scaling_available_governors"

It is working, but I am not sure the clock freq is really changed or not?

To change cpu voltage, you may:
echo "V" > cpu-voltage
V can be 900,1100,1200,1300,1400,1500, the value stored in show_frequency_and_voltage.
But I get problem like dvfm way when change cpu voltage.

To 2or0:
Is it possible to check the interface in the kernel and patch when you get time?
Please tell me,scaling functions are worked, or not?
« Last Edit: January 31, 2008, 11:08:31 pm by ecc_hy »
SL-C1000, Roku wifi, pdaxii13v2/Debian dual booting