This question already has an answer here:
I was stuck when trying to write to a system file to change the cpu frequency:
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed <unsupported> $ echo 1600000 | sudo tee /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed 1600000 tee: /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed: Invalid argument
Changing user to root has the same problem:
$ sudo su # echo 1600000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed bash: echo: write error: Invalid argument
The following should probably be unrelated. Previously, the above commands all worked, but then my Ubuntu was frozen an hour ago when I plug the usb plug of my laptop cooler into one usb port of my laptop, so I had to reboot it by hitting the power button of my laptop, and then I have the above problem.
Previously when it worked,
cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed output some value instead of
<unsupported>. After trying many times with the above
invalid argument error, now I just ran
echo 1600000 | sudo tee /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed once again, and it works without the
invalid argument error. Around the same time, ubuntu reported some cpu frequency utility error, which I don't remember exactly.