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How to fix the CPU frequency

Question asked by Steven Yu on Jan 19, 2019
Latest reply on Jan 20, 2019 by igorpadykov

Hi Support,

 

We found the CPU frequency is changing from time to time. We have checked Linux Reference Manual and realize it should be able to configure it, but we got following error. Do you know other way to fix the frequency setting ? 

 

root@imx6ull14x14evk:~# echo interactive > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

root@imx6ull14x14evk:~# cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq
528000
root@imx6ull14x14evk:~# cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq
198000
root@imx6ull14x14evk:~# cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq
528000


root@imx6ull14x14evk:~# echo 528000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed
-sh: echo: write error: Invalid argument

 

 

 

===imx6ull-14x14-evk.dts===

&cpu0 {
/*
* on i.MX6ULL, no seperated VDD_ARM_IN and VDD_SOC_IN,
* to align with other platform and use the same cpufreq
* driver, still use the seperated OPP define for arm
* and soc.
*/
operating-points = <
/* kHz uV */
528000 1175000
396000 1175000
198000 1175000
>;
fsl,soc-operating-points = <
/* KHz uV */
528000 1175000
396000 1175000
198000 1175000
>;
arm-supply = <&sw1c_reg>;
soc-supply = <&sw1c_reg>;
fsl,arm-soc-shared = <1>;
};

Regards,

Steven Yu

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