Power management fixes for 5.4-rc4

- Fix possible NULL pointer dereference in the ACPI processor
    scaling initialization code introduced by a recent cpufreq
    update (Rafael Wysocki).
 
  - Fix possible deadlock due to suspending cpufreq too late during
    system shutdown (Rafael Wysocki).
 
  - Make the PCI device system resume code path be more consistent
    with its PM-runtime counterpart to fix an issue with missing
    delay on transitions from D3cold to D0 during system resume from
    suspend-to-idle on some systems (Rafael Wysocki).
 
  - Drop Dell XPS13 9360 from the LPS0 Idle _DSM blacklist to make it
    use suspend-to-idle by default (Mario Limonciello).
 
  - Fix build warning in the core system suspend support code (Ben
    Dooks).
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Merge tag 'pm-5.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "These include a fix for a recent regression in the ACPI CPU
performance scaling code, a PCI device power management fix,
a system shutdown fix related to cpufreq, a removal of an ACPI
suspend-to-idle blacklist entry and a build warning fix.

Specifics:

   - Fix possible NULL pointer dereference in the ACPI processor scaling
     initialization code introduced by a recent cpufreq update (Rafael
     Wysocki).

   - Fix possible deadlock due to suspending cpufreq too late during
     system shutdown (Rafael Wysocki).

   - Make the PCI device system resume code path be more consistent with
     its PM-runtime counterpart to fix an issue with missing delay on
     transitions from D3cold to D0 during system resume from
     suspend-to-idle on some systems (Rafael Wysocki).

   - Drop Dell XPS13 9360 from the LPS0 Idle _DSM blacklist to make it
     use suspend-to-idle by default (Mario Limonciello).

   - Fix build warning in the core system suspend support code (Ben
     Dooks)"

* tag 'pm-5.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: processor: Avoid NULL pointer dereferences at init time
  PCI: PM: Fix pci_power_up()
  PM: sleep: include <linux/pm_runtime.h> for pm_wq
  cpufreq: Avoid cpufreq_suspend() deadlock on system shutdown
  ACPI: PM: Drop Dell XPS13 9360 from LPS0 Idle _DSM blacklist

drivers/acpi/processor_perflib.c

@@ -162,20 +162,22 @@ void acpi_processor_ppc_init(int cpu)
 	struct acpi_processor *pr = per_cpu(processors, cpu);
 	int ret;
 
+	if (!pr)
+		return;
+
 	ret = dev_pm_qos_add_request(get_cpu_device(cpu),
 				     &pr->perflib_req, DEV_PM_QOS_MAX_FREQUENCY,
 				     INT_MAX);
-	if (ret < 0) {
+	if (ret < 0)
 		pr_err("Failed to add freq constraint for CPU%d (%d)\n", cpu,
 		       ret);
-		return;
-	}
 }
 
 void acpi_processor_ppc_exit(int cpu)
 {
 	struct acpi_processor *pr = per_cpu(processors, cpu);
 
+	if (pr)
 		dev_pm_qos_remove_request(&pr->perflib_req);
 }
 

drivers/acpi/processor_thermal.c

@@ -130,20 +130,22 @@ void acpi_thermal_cpufreq_init(int cpu)
 	struct acpi_processor *pr = per_cpu(processors, cpu);
 	int ret;
 
+	if (!pr)
+		return;
+
 	ret = dev_pm_qos_add_request(get_cpu_device(cpu),
 				     &pr->thermal_req, DEV_PM_QOS_MAX_FREQUENCY,
 				     INT_MAX);
-	if (ret < 0) {
+	if (ret < 0)
 		pr_err("Failed to add freq constraint for CPU%d (%d)\n", cpu,
 		       ret);
-		return;
-	}
 }
 
 void acpi_thermal_cpufreq_exit(int cpu)
 {
 	struct acpi_processor *pr = per_cpu(processors, cpu);
 
+	if (pr)
 		dev_pm_qos_remove_request(&pr->thermal_req);
 }
 #else				/* ! CONFIG_CPU_FREQ */

drivers/acpi/sleep.c

@@ -361,19 +361,6 @@ static const struct dmi_system_id acpisleep_dmi_table[] __initconst = {
 		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_default_s3,
-	.ident = "Dell XPS13 9360",
-	.matches = {
-		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-		DMI_MATCH(DMI_PRODUCT_NAME, "XPS 13 9360"),
-		},
-	},
 	/*
 	 * ThinkPad X1 Tablet(2016) cannot do suspend-to-idle using
 	 * the Low Power S0 Idle firmware interface (see

drivers/base/core.c

@@ -9,6 +9,7 @@
  */
 
 #include <linux/acpi.h>
+#include <linux/cpufreq.h>
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/fwnode.h>
@@ -3179,6 +3180,8 @@ void device_shutdown(void)
 	wait_for_device_probe();
 	device_block_probing();
 
+	cpufreq_suspend();
+
 	spin_lock(&devices_kset->list_lock);
 	/*
 	 * Walk the devices list backward, shutting down each in turn.

drivers/cpufreq/cpufreq.c

@@ -2737,14 +2737,6 @@ int cpufreq_unregister_driver(struct cpufreq_driver *driver)
 }
 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
 
-/*
- * Stop cpufreq at shutdown to make sure it isn't holding any locks
- * or mutexes when secondary CPUs are halted.
- */
-static struct syscore_ops cpufreq_syscore_ops = {
-	.shutdown = cpufreq_suspend,
-};
-
 struct kobject *cpufreq_global_kobject;
 EXPORT_SYMBOL(cpufreq_global_kobject);
 
@@ -2756,8 +2748,6 @@ static int __init cpufreq_core_init(void)
 	cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj);
 	BUG_ON(!cpufreq_global_kobject);
 
-	register_syscore_ops(&cpufreq_syscore_ops);
-
 	return 0;
 }
 module_param(off, int, 0444);

drivers/pci/pci.c

@@ -958,19 +958,6 @@ void pci_refresh_power_state(struct pci_dev *dev)
 	pci_update_current_state(dev, dev->current_state);
 }
 
-/**
- * pci_power_up - Put the given device into D0 forcibly
- * @dev: PCI device to power up
- */
-void pci_power_up(struct pci_dev *dev)
-{
-	if (platform_pci_power_manageable(dev))
-		platform_pci_set_power_state(dev, PCI_D0);
-
-	pci_raw_set_power_state(dev, PCI_D0);
-	pci_update_current_state(dev, PCI_D0);
-}
-
 /**
  * pci_platform_power_transition - Use platform to change device power state
  * @dev: PCI device to handle.
@@ -1153,6 +1140,17 @@ int pci_set_power_state(struct pci_dev *dev, pci_power_t state)
 }
 EXPORT_SYMBOL(pci_set_power_state);
 
+/**
+ * pci_power_up - Put the given device into D0 forcibly
+ * @dev: PCI device to power up
+ */
+void pci_power_up(struct pci_dev *dev)
+{
+	__pci_start_power_transition(dev, PCI_D0);
+	pci_raw_set_power_state(dev, PCI_D0);
+	pci_update_current_state(dev, PCI_D0);
+}
+
 /**
  * pci_choose_state - Choose the power state of a PCI device
  * @dev: PCI device to be suspended

kernel/power/main.c

@@ -15,6 +15,7 @@
 #include <linux/seq_file.h>
 #include <linux/suspend.h>
 #include <linux/syscalls.h>
+#include <linux/pm_runtime.h>
 
 #include "power.h"