Pstate issue since Kernel 6.5.5

MikeK61

How can i check if the pstate driver is loaded ?
Since kernel update to 6.5.5 my Ryzen 1800 doesn`t downclock in idle sometimes.
Normally the CPU clocks at 2200MHZ in idle but after update to kernel 6.5.5 it clocks at 3600MHZ.
After the CVS patch it was normal for a few days again but after last update it happens again.
The CPU is not getting hot but uses more power.
Maybe another reboot could change it again, so i think it would be easier to check if pstate is active.

Any ideas ?

MikeK61

I have read amd pstate driver has changed in kernel 6.5.3.
Maybe something went wrong in 6.5.5.

How can i check if the amd pstate driver is loaded correctly ?

CPU is Ryzen 1800.

MikeK61

It seems pstate driver is not loaded.

mike@solus ~ $ cpupower frequency-info
CPU 8 wird analysiert:
driver: acpi-cpufreq
CPUs, die mit der gleichen Hardwarefrequenz laufen: 8
CPUs, die ihre Frequenz mit Software koordinieren müssen: 8
Maximale Dauer eines Taktfrequenzwechsels: Cannot determine or is not supported.
Hardwarebegrenzungen: 2.20 GHz - 3.60 GHz
available frequency steps: 3.60 GHz, 3.20 GHz, 2.20 GHz
verfügbare cpufreq-Regler: ondemand performance schedutil
momentane Richtlinie: Frequenz sollte innerhalb 2.20 GHz und 3.60 GHz.
sein. Der Regler "performance" kann frei entscheiden,
welche Geschwindigkeit er in diesem Bereich verwendet.
current CPU frequency: Unable to call hardware
current CPU frequency: 3.69 GHz (asserted by call to kernel)
boost state support:
Unterstützt: nein
Aktiv: nein

Staudey

Which DE are you using? Can you check if power-profiles-daemon is installed on your system?

MikeK61

I`m using Plasma edition and yes power-profiles-deamon is loaded.
And like i said it did work alreadywith this actual kernel.

Now i get this

modprobe amd-pstate
modprobe: FATAL: Module amd-pstate not found in directory /lib/modules/6.5.5-258.current

ReillyBrogan

MikeK61 amd-pstate is no longer built as a kernel module and is active by default for all supported CPUs. You can see if it's in use by doing cat /sys/devices/system/cpu/cpufreq/policy0/scaling_driver which should show some variant of amd-pstate if it's enabled.

MikeK61

Thanks for the reply ReillyBrogan.
All i get is

mike@solus ~ $ cat /sys/devices/system/cpu/cpufreq/policy0/scaling_driver
acpi-cpufreq

Like some suggestions iǜe read i added amd_pstate=passive to the grub file, but still no success.

ReillyBrogan

amd-pstate is only supported by Zen 2 and newer. Your CPU is a Zen 1 chip and it using the acpi-cpufreq driver instead is expected behavior. The reason your CPU is clocking higher is because we disabled our custom cpu-powersave daemon as it did not work with amd-pstate and nobody was interested in fixing it. You can achieve the same effect by clicking on the power icon in Plasma and choosing the left-most power profile. This should be persisted between boots, and you can change it on-demand as needed.

MikeK61

Thank you again.
That`s what i assumed.

After fiddling for hours i found this solution.
cpupower frequency-set -g schedutil

Works fine so far.

ReillyBrogan

MikeK61 Funny enough I was already going to switch the kernel to use schedutil by default in the next release.

MikeK61

Would be nice, especially for Zen 1 users like me.