Merge tag 'pm-6.12-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fix from Rafael Wysocki:
 "Fix the asymmetric CPU capacity support code in the intel_pstate
  driver, added during this develompent cycle, to address a corner case
  in which the capacity of a CPU going online is not updated (Rafael
  Wysocki)"

* tag 'pm-6.12-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: intel_pstate: Update asym capacity for CPUs that were offline initially
  cpufreq: intel_pstate: Clear hybrid_max_perf_cpu before driver registration

1 files changed, 23 insertions, 3 deletions

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index b0018f371ea3..cd2ac1ba53d2 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -1034,7 +1034,7 @@ static void __hybrid_init_cpu_capacity_scaling(void)
 	hybrid_update_cpu_capacity_scaling();
 }
 
-static void hybrid_init_cpu_capacity_scaling(void)
+static void hybrid_init_cpu_capacity_scaling(bool refresh)
 {
 	bool disable_itmt = false;
 
@@ -1045,7 +1045,7 @@ static void hybrid_init_cpu_capacity_scaling(void)
 	 * scaling has been enabled already and the driver is just changing the
 	 * operation mode.
 	 */
-	if (hybrid_max_perf_cpu) {
+	if (refresh) {
 		__hybrid_init_cpu_capacity_scaling();
 		goto unlock;
 	}
@@ -1071,6 +1071,18 @@ unlock:
 		sched_clear_itmt_support();
 }
 
+static bool hybrid_clear_max_perf_cpu(void)
+{
+	bool ret;
+
+	guard(mutex)(&hybrid_capacity_lock);
+
+	ret = !!hybrid_max_perf_cpu;
+	hybrid_max_perf_cpu = NULL;
+
+	return ret;
+}
+
 static void __intel_pstate_get_hwp_cap(struct cpudata *cpu)
 {
 	u64 cap;
@@ -2263,6 +2275,11 @@ static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
 		} else {
 			cpu->pstate.scaling = perf_ctl_scaling;
 		}
+		/*
+		 * If the CPU is going online for the first time and it was
+		 * offline initially, asym capacity scaling needs to be updated.
+		 */
+		hybrid_update_capacity(cpu);
 	} else {
 		cpu->pstate.scaling = perf_ctl_scaling;
 		cpu->pstate.max_pstate = pstate_funcs.get_max(cpu->cpu);
@@ -3352,6 +3369,7 @@ static void intel_pstate_driver_cleanup(void)
 
 static int intel_pstate_register_driver(struct cpufreq_driver *driver)
 {
+	bool refresh_cpu_cap_scaling;
 	int ret;
 
 	if (driver == &intel_pstate)
@@ -3364,6 +3382,8 @@ static int intel_pstate_register_driver(struct cpufreq_driver *driver)
 
 	arch_set_max_freq_ratio(global.turbo_disabled);
 
+	refresh_cpu_cap_scaling = hybrid_clear_max_perf_cpu();
+
 	intel_pstate_driver = driver;
 	ret = cpufreq_register_driver(intel_pstate_driver);
 	if (ret) {
@@ -3373,7 +3393,7 @@ static int intel_pstate_register_driver(struct cpufreq_driver *driver)
 
 	global.min_perf_pct = min_perf_pct_min();
 
-	hybrid_init_cpu_capacity_scaling();
+	hybrid_init_cpu_capacity_scaling(refresh_cpu_cap_scaling);
 
 	return 0;
 }