Bug 201045

Summary: Acer aspire 315-41g with ryzen 3 2200u runs constantly at turbo frequency after waking from suspend
Product: Power Management Reporter: siyia (eutychios23)
Component: cpufreqAssignee: linux-pm (linux-pm)
Status: RESOLVED INSUFFICIENT_DATA    
Severity: normal CC: eutychios23
Priority: P1    
Hardware: x86-64   
OS: Linux   
Kernel Version: 4.18.6 Subsystem:
Regression: No Bisected commit-id:

Description siyia 2018-09-08 12:50:07 UTC
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.

specs:
cpu ryzen 3 2200u
gpu1 vega 3
gpu2 radeon 535

archlinux kernel 4.18.6 mainline

boot parameters "ivrs_ioapic[4]=00:14.0 ivrs_ioapic[5]=00:00.2"
Comment 1 siyia 2018-09-08 18:30:09 UTC
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.
Comment 2 siyia 2018-09-09 07:28:51 UTC
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?
Comment 3 siyia 2018-09-14 10:24:01 UTC
specifically you need to set power_bias from 0 to 1 in order for ondemand governor to scale up and down according to load.
Comment 4 siyia 2018-10-15 12:03:49 UTC
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
Comment 5 siyia 2018-10-15 13:10:40 UTC
i was wrong fixed in kernel 4.18.14
Comment 6 siyia 2018-10-15 13:29:21 UTC
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.
Comment 7 siyia 2018-10-15 13:32:37 UTC
resuming from suspend though disables cpupowersave and cpu runs at turbo frequency again.
Comment 8 siyia 2018-12-30 20:12:20 UTC
with ioapic remaping and kernel 4.20 powersave seems to work after suspend