Why don't kernels nowadays support voltage control?

[Logi_Ca1]

Voltage control has been a thing in the past, allowing us to undervolt the CPU and save power. I notice that this hasn't been a feature in custom kernels since the Snapdragon 820 days. Has Qualcomm locked this down?

 

[cultofluna]

On the new processors..like sd820 or 821....is not more efficient....
That's why the developers they dont use it anymore...

 

[weter11]

Who said, that it is impossible? Qualcomm didn't open source only GPU and modem drivers and some other proprietary stuff, but CPU and GPU voltage is possible to change. You only need to clone kernel on github (for example franco) and add commits from another Snap 820 kernel which add voltage table and changeable CPU voltage. Kernel adiutor works very good, at least latest version on market. Also it is possible to change GPU voltage, but I didn't find how to do that on modern GPUs, except compile kernel with some values, and wait would it boot or not. I'm also waiting when someone give its voltage table from that 10nm SoC, because on Anandtech no any article with it.