Merge tag 'pm-4.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
"These fix two regressions introduced recently, one by reverting the
problematic commit and one by fixing up the behavior in an overlooked
case.

Specifics:

- Revert the recent change that caused suspend-to-idle to be used as
the default suspend method on systems where it is indicated to be
efficient by the ACPI tables, as that turned out to be premature
and introduced suspend regressions on some systems with missing
power management support in device drivers (Rafael Wysocki).

- Fix up the intel_pstate driver to take changes of the global limits
via sysfs correctly when the performance policy is used which has
been broken by a recent change in it (Srinivas Pandruvada)"

* tag 'pm-4.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpufreq: intel_pstate: Fix sysfs limits enforcement for performance policy
Revert "PM / sleep / ACPI: Use the ACPI_FADT_LOW_POWER_S0 flag"

Documentation/power/states.txt

···
 The default suspend mode (ie. the one to be used without writing anything into
 /sys/power/mem_sleep) is either "deep" (if Suspend-To-RAM is supported) or
 "s2idle", but it can be overridden by the value of the "mem_sleep_default"
-parameter in the kernel command line.  On some ACPI-based systems, depending on
-the information in the FADT, the default may be "s2idle" even if Suspend-To-RAM
-is supported.
+parameter in the kernel command line.
 
 The properties of all of the sleep states are described below.
 

drivers/acpi/sleep.c

···
 		if (acpi_sleep_state_supported(i))
 			sleep_states[i] = 1;
 
-	/*
-	 * Use suspend-to-idle by default if ACPI_FADT_LOW_POWER_S0 is set and
-	 * the default suspend mode was not selected from the command line.
-	 */
-	if (acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0 &&
-	    mem_sleep_default > PM_SUSPEND_MEM)
-		mem_sleep_default = PM_SUSPEND_FREEZE;
-
 	suspend_set_ops(old_suspend_ordering ?
 		&acpi_suspend_ops_old : &acpi_suspend_ops);
 	freeze_set_ops(&acpi_freeze_ops);

drivers/cpufreq/intel_pstate.c

···
 			limits = &performance_limits;
 			perf_limits = limits;
 		}
-		if (policy->max >= policy->cpuinfo.max_freq) {
+		if (policy->max >= policy->cpuinfo.max_freq &&
+		    !limits->no_turbo) {
 			pr_debug("set performance\n");
 			intel_pstate_set_performance_limits(perf_limits);
 			goto out;
···
 	if (policy->policy != CPUFREQ_POLICY_POWERSAVE &&
 	    policy->policy != CPUFREQ_POLICY_PERFORMANCE)
 		return -EINVAL;
+
+	/* When per-CPU limits are used, sysfs limits are not used */
+	if (!per_cpu_limits) {
+		unsigned int max_freq, min_freq;
+
+		max_freq = policy->cpuinfo.max_freq *
+						limits->max_sysfs_pct / 100;
+		min_freq = policy->cpuinfo.max_freq *
+						limits->min_sysfs_pct / 100;
+		cpufreq_verify_within_limits(policy, min_freq, max_freq);
+	}
 
 	return 0;
 }

include/linux/suspend.h

···
 };
 
 #ifdef CONFIG_SUSPEND
-extern suspend_state_t mem_sleep_default;
-
 /**
  * suspend_set_ops - set platform dependent suspend operations
  * @ops: The new suspend operations to set.

kernel/power/suspend.c

···
 const char *mem_sleep_states[PM_SUSPEND_MAX];
 
 suspend_state_t mem_sleep_current = PM_SUSPEND_FREEZE;
-suspend_state_t mem_sleep_default = PM_SUSPEND_MAX;
+static suspend_state_t mem_sleep_default = PM_SUSPEND_MEM;
 
 unsigned int pm_suspend_global_flags;
 EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
···
 	}
 	if (valid_state(PM_SUSPEND_MEM)) {
 		mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM];
-		if (mem_sleep_default >= PM_SUSPEND_MEM)
+		if (mem_sleep_default == PM_SUSPEND_MEM)
 			mem_sleep_current = PM_SUSPEND_MEM;
 	}