Hello the cpu frequency of my laptop seems to always run on turbo boost frequency when my laptop has the ac plugged according to lscpu, when running on battery cpu scales dynamically according to load like it is supposed to.
cpu ryzen 3 2200u
gpu1 vega 3
gpu2 radeon 535
archlinux kernel 4.18.6 mainline
boot parameters "ivrs_ioapic=00:14.0 ivrs_ioapic=00:00.2"
OK after further testing governors: schedutil on demand and conservative cannot scale down from turbo frequency.
powersave governor stays steadily at half the turbo speed 1.6ghz when set.
after some trial and error i switched governor to ondemand using cpu power and enabled the power save feature now the cpu scales according to system load. The issue however remains why are powersave features not implemented for my cpu by default with ondemand and schedutil governors?
specifically you need to set power_bias from 0 to 1 in order for ondemand governor to scale up and down according to load.
adding rcu_nocbs=0-N and idle=nowait boot parameters enables the powersave cpu feature (N is number of cores - 1) for all cpu governors
i was wrong fixed in kernel 4.18.14
early load of amdgpu module in kms actually fixed the power save issue add amdgpu in mkinitcpio.conf modules and sudo mkinitcpio -p linux then reboot.
resuming from suspend though disables cpupowersave and cpu runs at turbo frequency again.
with ioapic remaping and kernel 4.20 powersave seems to work after suspend