Way to control boost states on Stoney Ridge ( careena )

Hi!

Just installed EndeavourOS with the patched 6.6.16-stoney kernel on my careena chromebook, after Full Rom flash.

Everything works perfectly - sound, touchpad, suspend, function keys etc. The only problem is that the laptop gets very hot, even with the governor set to “conservative.” The cpu(a4-9120c) boosts for a prolonged time to 2.4Ghz, even when watching a 720p youtube video at 30% usage. (on ChromeOS I don’t think I ever saw it boost past 2.2Ghz, and at sustained load it would peg to 1.8Ghz)

“$ cpupower frequency-info” shows:

boost state support:
Supported: yes
Active: yes
Boost States: 4
Total States: 8
Pstate-Pb0: 2400MHz (boost state)
Pstate-Pb1: 2200MHz (boost state)
Pstate-Pb2: 2000MHz (boost state)
Pstate-Pb3: 1800MHz (boost state)
Pstate-P0: 1600MHz
Pstate-P1: 1400MHz
Pstate-P2: 1200MHz

The cpu can be limited to 1.2Ghz or 1.4Ghz with “$ cpupower frequency-set --max 1400mhz” but at 1600mhz and beyond it starts boosting again all the way up to 2.4Ghz.

Is there a way to limit the boosting frequency? I’ve already tried editing the /cpufreq/boost file from 1 to 0, but it doesn’t work. I’d happily settle for disabling boost states and have it run at max 1.6Ghz instead of just 1.4. Even better would to a way to disable the 2.4Ghz boost state.
Thanks.

Update: I removed ‘power-profiles-daemon’ that came default and installed tuneD, after setting their ‘laptop-battery-powersave’ profile, cpu no longer boosts to 2.4Ghz for longer than a second while having a few tabs open + 720p youtube video playing.

A quick benchmark shows around a 1W reduction in power consumption(from ~8.2 to ~7.2). I’ll use it for a bit, to see if it’s not a placebo fix.

Jacob(1) here, sorry forgot the password to the previous account.

After a lot of testing here’s the best way I found to get good battery life + responsiveness on careena(and probably all the other stoney ridge chromebooks):

-TuneD, or any specific power manager, not needed

-kernel parameters: cpufreq.default_governor=conservative and mitigations=off(might not be doing anything for battery)

-edit 2 files “/sys/devices/system/cpu/cpufreq/conservative/down_threshold” and “up_threshold”
“down_threshold” at 70, “up_threshold” at 90, this means that the cpu will lower its’ frequency when at or below 70% usage and boost only when at 90%+, ofc this can be adjusted down if you want more responsiveness.

Those values reset on restart, you can make an .sh script to automate it:
#!/bin/sh
echo -n 70 | sudo tee /sys/devices/system/cpu/cpufreq/conservative/down_threshold
echo -n 90 | sudo tee /sys/devices/system/cpu/cpufreq/conservative/up_threshold

That’s it, all the other methods I tried did not seem to be doing much.

hi Jacob,
I’m not an expert in this field so ask @MrChromebox, (take everything I say with a grain of salt) but I think this is an issue with the os/acpi