From 918229cdd5abb50d8a2edfcd8dc6b6bc53afd765 Mon Sep 17 00:00:00 2001 From: Giovanni Gherdovich Date: Wed, 22 Jan 2020 16:16:17 +0100 Subject: x86/intel_pstate: Handle runtime turbo disablement/enablement in frequency invariance On some platforms such as the Dell XPS 13 laptop the firmware disables turbo when the machine is disconnected from AC, and viceversa it enables it again when it's reconnected. In these cases a _PPC ACPI notification is issued. The scheduler needs to know freq_max for frequency-invariant calculations. To account for turbo availability to come and go, record freq_max at boot as if turbo was available and store it in a helper variable. Use a setter function to swap between freq_base and freq_max every time turbo goes off or on. Signed-off-by: Giovanni Gherdovich Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Acked-by: Rafael J. Wysocki Link: https://lkml.kernel.org/r/20200122151617.531-7-ggherdovich@suse.cz --- drivers/cpufreq/intel_pstate.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/cpufreq/intel_pstate.c') diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index d2fa3e9ccd97..abbeeca8bb3b 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -922,6 +922,7 @@ static void intel_pstate_update_limits(unsigned int cpu) */ if (global.turbo_disabled_mf != global.turbo_disabled) { global.turbo_disabled_mf = global.turbo_disabled; + arch_set_max_freq_ratio(global.turbo_disabled); for_each_possible_cpu(cpu) intel_pstate_update_max_freq(cpu); } else { -- cgit v1.2.3