Fixing random resets; overclocking

Some tablets can reboot frequently, when there is hard task in progress, for example package updating. It is caused by too high CPU frequency - default setting is 300-1200MHz, but A10 can max. handle… 1.2GHz (after overclocking!).

The solution is to change maximum frequency to other value, for example 1008MHz.

Fixing bug

To fix the problem, you have to open file /etc/init.d/cubian-ondemandcpufreq in nano, as root or as sudo.

Then, find a line

echo -n 1200000 > /sys/devices/system/cpu/${cpu}/cpufreq/scaling_max_freq

and change value to for example

echo -n 1008000 > /sys/devices/system/cpu/${cpu}/cpufreq/scaling_max_freq

Values are given in kHz!!! Then save file (^X, Y, ENTER) and reboot system.

Overclocking and underclocking

You can use this file also to overclock or underclock your CPU and change the governor!

Details about frequencies and governors

To print a list of available frequencies, type command:

cat /sys/devices/system/cpu/${cpu}/cpufreq/scaling_available_frequencies
  • Avoid using values less than 100000kHz or more than 1200000kHz!
  • Do not set minimal frequency higher than maximal, or vice versa!

To print a list of available governors, type command:

cat /sys/devices/system/cpu/${cpu}/cpufreq/scaling_available_governors

I recommend these governors:

  • ondemand/poversave - longer battery life, but lower performance, hard to get maximal frequency
  • fantasy - trying to keep good performance and save energy
  • performance - CPU is in overdrive, but may cause battery drains, good when you are using power adaptor

Changes

Then you can open file /etc/init.d/cubian-ondemandcpufreq in nano, as root or as sudo and change values:

Changing minimal frequency

echo -n XXXXXX > /sys/devices/system/cpu/${cpu}/cpufreq/scaling_min_freq

Changing maximal frequency

echo -n XXXXXX > /sys/devices/system/cpu/${cpu}/cpufreq/scaling_max_freq

Changing governor

echo -n XXXXXX > /sys/devices/system/cpu/${cpu}/cpufreq/scaling_governor