It's nice that you can now replace acpi-cpufreq with amd-pstate using replace=1 but what about the opposite? Can it be done without rebooting if acpi-cpufreq is built-in? Would be really nice to have. Meanwhile some sort of power managerment still works after `rmmod amd-pstate` because I see that reported frequencies in /proc/cpuinfo change: one or two random cores are oscillating between 1700 and 2000MHz, all the others are stuck at 3800MHz.
Huang Rui, Is this doable or I'm asking too much?
This is still relevant as of Linux 6.6. Would be great if removing amd-pstate enabled acpi-cpufreq.
(In reply to Artem S. Tashkinov from comment #2) > This is still relevant as of Linux 6.6. > > Would be great if removing amd-pstate enabled acpi-cpufreq. Normally the system hardware needs to reinitialize CPPC and low-level power management firmware when CPPC driver loading, so it better to change grub parameters and reboot again. dynamically removing amd-pstate and load acpi_cpufreq probably cause some potential issues. Perry.
(In reply to Perry Yuan(AMD) from comment #3) > (In reply to Artem S. Tashkinov from comment #2) > > This is still relevant as of Linux 6.6. > > > > Would be great if removing amd-pstate enabled acpi-cpufreq. > > Normally the system hardware needs to reinitialize CPPC and low-level power > management firmware when CPPC driver loading, so it better to change grub > parameters and reboot again. > dynamically removing amd-pstate and load acpi_cpufreq probably cause some > potential issues. > > Perry. Could you add this as a note to the amd pstate driver documentation? Documentation/admin-guide/pm/amd-pstate.rst Thank you!
(In reply to Artem S. Tashkinov from comment #4) > (In reply to Perry Yuan(AMD) from comment #3) > > (In reply to Artem S. Tashkinov from comment #2) > > > This is still relevant as of Linux 6.6. > > > > > > Would be great if removing amd-pstate enabled acpi-cpufreq. > > > > Normally the system hardware needs to reinitialize CPPC and low-level power > > management firmware when CPPC driver loading, so it better to change grub > > parameters and reboot again. > > dynamically removing amd-pstate and load acpi_cpufreq probably cause some > > potential issues. > > > > Perry. > > Could you add this as a note to the amd pstate driver documentation? > > Documentation/admin-guide/pm/amd-pstate.rst > > Thank you! Sure, we can add this to amd-pstate.rst with a new update. Perry.