[TRACKING] PPD v TLP for AMD Ryzen 7040

[Mario_Limonciello]

@Clement_Marche

1. I get that ppd and amdpstate are now kind of “linked” thanks to the ppa. However can we get a better view on what is set by the ppd ? For instance : min/max fresquencies ? Turbo core on/off ? etc.

You can look at the PPD and Framework’s EC source code to see exactly what is changed. To summarize it, changing the slider will now:

1. Set the EPP preference, which is a bias described here: amd-pstate CPU Performance Scaling Driver — The Linux Kernel documentation
2. Set the CPUFreq scaling governor to either powersave or performance.
3. Set the ACPI platform profile. This will use the amd-pmf driver to notify Framework’s EC to change CPU coefficients. The exact changes made are described here: EmbeddedController/zephyr/program/lotus/azalea/src/cpu_power.c at lotus-zephyr · FrameworkComputer/EmbeddedController · GitHub

@Clement_Marche

2. Since I’m not sure what the power profile allows and prevents exactly, it’s more an observation than a fact but it seems that after suspend eventhough I’m in “nergy saver” I get higher frequency than expected. After I reapply the profile (change it to another one then change it back), it seems fine.

This sure sounds like a kernel bug to me. Can you reproduce it on 6.7-rc7? If so; would you please file a kernel bugzilla with all the details from the command cpupower frequency-info before and after suspend?

NOTE: Unfortunately using this command is a little awkward on the Ubuntu mainline PPA, you might need to compile from scratch to get the tool.