ACPI / PM: Run wakeup notify handlers synchronously

The work functions provided by the users of acpi_add_pm_notifier()
should be run synchronously before re-enabling the wakeup GPE in
case they are used to clear the status and/or disable the wakeup
signaling at the source.  Otherwise, which is the case currently in
the PCI bus type code, the same wakeup event may be signaled for
multiple times while the execution of the work function in response
to it has already been queued up.

Fortunately, acpi_add_pm_notifier() is only used by PCI and by
ACPI device PM code internally, so the change is relatively
straightforward to make.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/acpi/device_pm.c

@@ -400,8 +400,8 @@ static void acpi_pm_notify_handler(acpi_handle handle, u32 val, void *not_used)
 
 	if (adev->wakeup.flags.notifier_present) {
 		__pm_wakeup_event(adev->wakeup.ws, 0);
-		if (adev->wakeup.context.work.func)
-			queue_pm_work(&adev->wakeup.context.work);
+		if (adev->wakeup.context.func)
+			adev->wakeup.context.func(&adev->wakeup.context);
 	}
 
 	mutex_unlock(&acpi_pm_notifier_lock);
@@ -413,7 +413,7 @@ static void acpi_pm_notify_handler(acpi_handle handle, u32 val, void *not_used)
  * acpi_add_pm_notifier - Register PM notify handler for given ACPI device.
  * @adev: ACPI device to add the notify handler for.
  * @dev: Device to generate a wakeup event for while handling the notification.
- * @work_func: Work function to execute when handling the notification.
+ * @func: Work function to execute when handling the notification.
  *
  * NOTE: @adev need not be a run-wake or wakeup device to be a valid source of
  * PM wakeup events.  For example, wakeup events may be generated for bridges
@@ -421,11 +421,11 @@ static void acpi_pm_notify_handler(acpi_handle handle, u32 val, void *not_used)
  * bridge itself doesn't have a wakeup GPE associated with it.
  */
 acpi_status acpi_add_pm_notifier(struct acpi_device *adev, struct device *dev,
-				 void (*work_func)(struct work_struct *work))
+			void (*func)(struct acpi_device_wakeup_context *context))
 {
 	acpi_status status = AE_ALREADY_EXISTS;
 
-	if (!dev && !work_func)
+	if (!dev && !func)
 		return AE_BAD_PARAMETER;
 
 	mutex_lock(&acpi_pm_notifier_lock);
@@ -435,8 +435,7 @@ acpi_status acpi_add_pm_notifier(struct acpi_device *adev, struct device *dev,
 
 	adev->wakeup.ws = wakeup_source_register(dev_name(&adev->dev));
 	adev->wakeup.context.dev = dev;
-	if (work_func)
-		INIT_WORK(&adev->wakeup.context.work, work_func);
+	adev->wakeup.context.func = func;
 
 	status = acpi_install_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY,
 					     acpi_pm_notify_handler, NULL);
@@ -469,10 +468,7 @@ acpi_status acpi_remove_pm_notifier(struct acpi_device *adev)
 	if (ACPI_FAILURE(status))
 		goto out;
 
-	if (adev->wakeup.context.work.func) {
-		cancel_work_sync(&adev->wakeup.context.work);
-		adev->wakeup.context.work.func = NULL;
-	}
+	adev->wakeup.context.func = NULL;
 	adev->wakeup.context.dev = NULL;
 	wakeup_source_unregister(adev->wakeup.ws);
 
@@ -658,16 +654,15 @@ EXPORT_SYMBOL(acpi_pm_device_sleep_state);
 
 /**
  * acpi_pm_notify_work_func - ACPI devices wakeup notification work function.
- * @work: Work item to handle.
+ * @context: Device wakeup context.
  */
-static void acpi_pm_notify_work_func(struct work_struct *work)
+static void acpi_pm_notify_work_func(struct acpi_device_wakeup_context *context)
 {
-	struct device *dev;
+	struct device *dev = context->dev;
 
-	dev = container_of(work, struct acpi_device_wakeup_context, work)->dev;
 	if (dev) {
 		pm_wakeup_event(dev, 0);
-		pm_runtime_resume(dev);
+		pm_request_resume(dev);
 	}
 }
 

drivers/pci/pci-acpi.c

@@ -395,29 +395,26 @@ bool pciehp_is_native(struct pci_dev *pdev)
 
 /**
  * pci_acpi_wake_bus - Root bus wakeup notification fork function.
- * @work: Work item to handle.
+ * @context: Device wakeup context.
  */
-static void pci_acpi_wake_bus(struct work_struct *work)
+static void pci_acpi_wake_bus(struct acpi_device_wakeup_context *context)
 {
 	struct acpi_device *adev;
 	struct acpi_pci_root *root;
 
-	adev = container_of(work, struct acpi_device, wakeup.context.work);
+	adev = container_of(context, struct acpi_device, wakeup.context);
 	root = acpi_driver_data(adev);
 	pci_pme_wakeup_bus(root->bus);
 }
 
 /**
  * pci_acpi_wake_dev - PCI device wakeup notification work function.
- * @handle: ACPI handle of a device the notification is for.
- * @work: Work item to handle.
+ * @context: Device wakeup context.
  */
-static void pci_acpi_wake_dev(struct work_struct *work)
+static void pci_acpi_wake_dev(struct acpi_device_wakeup_context *context)
 {
-	struct acpi_device_wakeup_context *context;
 	struct pci_dev *pci_dev;
 
-	context = container_of(work, struct acpi_device_wakeup_context, work);
 	pci_dev = to_pci_dev(context->dev);
 
 	if (pci_dev->pme_poll)
@@ -425,7 +422,7 @@ static void pci_acpi_wake_dev(struct work_struct *work)
 
 	if (pci_dev->current_state == PCI_D3cold) {
 		pci_wakeup_event(pci_dev);
-		pm_runtime_resume(&pci_dev->dev);
+		pm_request_resume(&pci_dev->dev);
 		return;
 	}
 
@@ -434,7 +431,7 @@ static void pci_acpi_wake_dev(struct work_struct *work)
 		pci_check_pme_status(pci_dev);
 
 	pci_wakeup_event(pci_dev);
-	pm_runtime_resume(&pci_dev->dev);
+	pm_request_resume(&pci_dev->dev);
 
 	pci_pme_wakeup_bus(pci_dev->subordinate);
 }

include/acpi/acpi_bus.h

@@ -319,7 +319,7 @@ struct acpi_device_wakeup_flags {
 };
 
 struct acpi_device_wakeup_context {
-	struct work_struct work;
+	void (*func)(struct acpi_device_wakeup_context *context);
 	struct device *dev;
 };
 
@@ -599,7 +599,7 @@ static inline bool acpi_device_always_present(struct acpi_device *adev)
 
 #ifdef CONFIG_PM
 acpi_status acpi_add_pm_notifier(struct acpi_device *adev, struct device *dev,
-				 void (*work_func)(struct work_struct *work));
+			void (*func)(struct acpi_device_wakeup_context *context));
 acpi_status acpi_remove_pm_notifier(struct acpi_device *adev);
 int acpi_pm_device_sleep_state(struct device *, int *, int);
 int acpi_pm_device_run_wake(struct device *, bool);