Merge tag 'pm-final-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull final power management fixes from Rafael Wysocki:
"These fix a regression in the schedutil cpufreq governor introduced by
a recent change and blacklist Dell XPS13 9360 from using the Low Power
S0 Idle _DSM interface which triggers serious problems on one of these
machines.

Specifics:

- Prevent the schedutil cpufreq governor from using the utilization
of a wrong CPU in some cases which started to happen after one of
the recent changes in it (Chris Redpath).

- Blacklist Dell XPS13 9360 from using the Low Power S0 Idle _DSM
interface as that causes serious issue (related to NVMe) to appear
on one of these machines, even though the other Dells XPS13 9360 in
somewhat different HW configurations behave correctly (Rafael
Wysocki)"

* tag 'pm-final-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI / PM: Blacklist Low Power S0 Idle _DSM for Dell XPS13 9360
cpufreq: schedutil: Examine the correct CPU when we update util

drivers/acpi/sleep.c

···
 	return 0;
 }
 
+static bool acpi_sleep_no_lps0;
+
+static int __init init_no_lps0(const struct dmi_system_id *d)
+{
+	acpi_sleep_no_lps0 = true;
+	return 0;
+}
+
 static const struct dmi_system_id acpisleep_dmi_table[] __initconst = {
 	{
 	.callback = init_old_suspend_ordering,
···
 		DMI_MATCH(DMI_PRODUCT_NAME, "80E3"),
 		},
 	},
+	/*
+	 * https://bugzilla.kernel.org/show_bug.cgi?id=196907
+	 * Some Dell XPS13 9360 cannot do suspend-to-idle using the Low Power
+	 * S0 Idle firmware interface.
+	 */
+	{
+	.callback = init_no_lps0,
+	.ident = "Dell XPS13 9360",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "XPS 13 9360"),
+		},
+	},
 	{},
 };
 
···
 }
 #else /* !CONFIG_ACPI_SLEEP */
 #define acpi_target_sleep_state	ACPI_STATE_S0
+#define acpi_sleep_no_lps0	(false)
 static inline void acpi_sleep_dmi_check(void) {}
 #endif /* CONFIG_ACPI_SLEEP */
 
···
 
 	if (lps0_device_handle)
 		return 0;
+
+	if (acpi_sleep_no_lps0) {
+		acpi_handle_info(adev->handle,
+				 "Low Power S0 Idle interface disabled\n");
+		return 0;
+	}
 
 	if (!(acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0))
 		return 0;

kernel/sched/cpufreq_schedutil.c

···
 		struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu);
 
 		memset(sg_cpu, 0, sizeof(*sg_cpu));
+		sg_cpu->cpu = cpu;
 		sg_cpu->sg_policy = sg_policy;
 		sg_cpu->flags = SCHED_CPUFREQ_RT;
 		sg_cpu->iowait_boost_max = policy->cpuinfo.max_freq;
···
 
 static int __init sugov_register(void)
 {
-	int cpu;
-
-	for_each_possible_cpu(cpu)
-		per_cpu(sugov_cpu, cpu).cpu = cpu;
-
 	return cpufreq_register_governor(&schedutil_gov);
 }
 fs_initcall(sugov_register);