A13-SOM lowering CPU frequency

Started by ulink, September 17, 2014, 07:34:07 PM

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ulink

Is ist possible to set the CPU frequency down to 500Mhz or something using a Linux config file (maybe script.fex/script.bin)?

MBR

I'm not sure. but on A13 it seem that currenlty the only way is modifin the FEX file and set the speed there, see http://linux-sunxi.org/Fex_Guide. For the A20, there is the cpufreq support in the kernel, so you can set the frequeny on the fly.

ulink

Quote from: MBR on September 18, 2014, 07:47:03 AM
I'm not sure. but on A13 it seem that currenlty the only way is modifin the FEX file and set the speed there, see http://linux-sunxi.org/Fex_Guide. For the A20, there is the cpufreq support in the kernel, so you can set the frequeny on the fly.
Tried to change "boot_clock" entry without luck  :(

ulink

Found a solution: Set kernel configuration (.config file) CONFIG_CPU_FREQ=y and CONFIG_CPU_IDLE=y, recompiled the kernel and installed it to the SD card.

Show some infos (including valid clocks): /usr/bin/cpufreq-info
Set CPU clock to 264Mhz: /usr/bin/cpufreq-set -f 264Mhz