Merge tag 'pm-5.2-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
"These fix three issues in the system-wide suspend and hibernation area
related to PCI device PM handling by suspend-to-idle, device wakeup
optimizations and arbitrary differences between suspend and
hiberantion.

Specifics:

- Modify the PCI bus type's PM code to avoid putting devices left by
their drivers in D0 on purpose during suspend to idle into
low-power states as doing that may confuse the system resume
callbacks of the drivers in question (Rafael Wysocki).

- Avoid checking ACPI wakeup configuration during system-wide suspend
for suspended devices that do not use ACPI-based wakeup to allow
them to stay in suspend more often (Rafael Wysocki).

- The last phase of hibernation is analogous to system-wide suspend
also because on platforms with ACPI it passes control to the
platform firmware to complete the transision, so make it indicate
that by calling pm_set_suspend_via_firmware() to allow the drivers
that care about this to do the right thing (Rafael Wysocki)"

* tag 'pm-5.2-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PCI: PM: Avoid possible suspend-to-idle issue
ACPI: PM: Call pm_set_suspend_via_firmware() during hibernation
ACPI/PCI: PM: Add missing wakeup.flags.valid checks

drivers/acpi/device_pm.c

···
 	u32 sys_target = acpi_target_system_state();
 	int ret, state;
 
-	if (!pm_runtime_suspended(dev) || !adev ||
-	    device_may_wakeup(dev) != !!adev->wakeup.prepare_count)
+	if (!pm_runtime_suspended(dev) || !adev || (adev->wakeup.flags.valid &&
+	    device_may_wakeup(dev) != !!adev->wakeup.prepare_count))
 		return true;
 
 	if (sys_target == ACPI_STATE_S0)

drivers/acpi/sleep.c

···
 	nosigcheck = true;
 }
 
-static int acpi_hibernation_begin(void)
+static int acpi_hibernation_begin(pm_message_t stage)
 {
-	int error;
+	if (!nvs_nosave) {
+		int error = suspend_nvs_alloc();
+		if (error)
+			return error;
+	}
 
-	error = nvs_nosave ? 0 : suspend_nvs_alloc();
-	if (!error)
-		acpi_pm_start(ACPI_STATE_S4);
+	if (stage.event == PM_EVENT_HIBERNATE)
+		pm_set_suspend_via_firmware();
 
-	return error;
+	acpi_pm_start(ACPI_STATE_S4);
+	return 0;
 }
 
 static int acpi_hibernation_enter(void)
···
  *		function is used if the pre-ACPI 2.0 suspend ordering has been
  *		requested.
  */
-static int acpi_hibernation_begin_old(void)
+static int acpi_hibernation_begin_old(pm_message_t stage)
 {
 	int error;
 	/*
···
 	acpi_sleep_tts_switch(ACPI_STATE_S4);
 
 	error = acpi_sleep_prepare(ACPI_STATE_S4);
+	if (error)
+		return error;
 
-	if (!error) {
-		if (!nvs_nosave)
-			error = suspend_nvs_alloc();
-		if (!error) {
-			acpi_target_sleep_state = ACPI_STATE_S4;
-			acpi_scan_lock_acquire();
-		}
+	if (!nvs_nosave) {
+		error = suspend_nvs_alloc();
+		if (error)
+			return error;
 	}
-	return error;
+
+	if (stage.event == PM_EVENT_HIBERNATE)
+		pm_set_suspend_via_firmware();
+
+	acpi_target_sleep_state = ACPI_STATE_S4;
+	acpi_scan_lock_acquire();
+	return 0;
 }
 
 /*

drivers/pci/pci-acpi.c

···
 	if (!adev || !acpi_device_power_manageable(adev))
 		return false;
 
-	if (device_may_wakeup(&dev->dev) != !!adev->wakeup.prepare_count)
+	if (adev->wakeup.flags.valid &&
+	    device_may_wakeup(&dev->dev) != !!adev->wakeup.prepare_count)
 		return true;
 
 	if (acpi_target_system_state() == ACPI_STATE_S0)

drivers/pci/pci-driver.c

···
 	struct pci_dev *pci_dev = to_pci_dev(dev);
 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 
+	pci_dev->skip_bus_pm = false;
+
 	if (pci_has_legacy_pm_support(pci_dev))
 		return pci_legacy_suspend(dev, PMSG_SUSPEND);
 
···
 		}
 	}
 
-	if (!pci_dev->state_saved) {
+	if (pci_dev->skip_bus_pm) {
+		/*
+		 * The function is running for the second time in a row without
+		 * going through full resume, which is possible only during
+		 * suspend-to-idle in a spurious wakeup case.  Moreover, the
+		 * device was originally left in D0, so its power state should
+		 * not be changed here and the device register values saved
+		 * originally should be restored on resume again.
+		 */
+		pci_dev->state_saved = true;
+	} else if (pci_dev->state_saved) {
+		if (pci_dev->current_state == PCI_D0)
+			pci_dev->skip_bus_pm = true;
+	} else {
 		pci_save_state(pci_dev);
 		if (pci_power_manageable(pci_dev))
 			pci_prepare_to_sleep(pci_dev);

include/linux/pci.h

···
 						   D3cold, not set for devices
 						   powered on/off by the
 						   corresponding bridge */
+	unsigned int	skip_bus_pm:1;	/* Internal: Skip bus-level PM */
 	unsigned int	ignore_hotplug:1;	/* Ignore hotplug events */
 	unsigned int	hotplug_user_indicators:1; /* SlotCtl indicators
 						      controlled exclusively by

include/linux/suspend.h

···
  *	platforms which require special recovery actions in that situation.
  */
 struct platform_hibernation_ops {
-	int (*begin)(void);
+	int (*begin)(pm_message_t stage);
 	void (*end)(void);
 	int (*pre_snapshot)(void);
 	void (*finish)(void);

kernel/power/hibernate.c

···
 static int platform_begin(int platform_mode)
 {
 	return (platform_mode && hibernation_ops) ?
-		hibernation_ops->begin() : 0;
+		hibernation_ops->begin(PMSG_FREEZE) : 0;
 }
 
 /**
···
 	 * hibernation_ops->finish() before saving the image, so we should let
 	 * the firmware know that we're going to enter the sleep state after all
 	 */
-	error = hibernation_ops->begin();
+	error = hibernation_ops->begin(PMSG_HIBERNATE);
 	if (error)
 		goto Close;