PCI/ACPI/PM: Avoid resuming devices that don't signal PME

Modify pci_acpi_wake_dev() to avoid resuming PME-capable devices
whose PME Status bits are not set, which may happen currently if
several devices are associated with the same wakeup GPE and all
of them are notified whenever at least one of them signals PME.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index c8e7585..060fd22 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -45,16 +45,20 @@
 {
 	struct pci_dev *pci_dev = context;
 
-	if (event == ACPI_NOTIFY_DEVICE_WAKE && pci_dev) {
+	if (event != ACPI_NOTIFY_DEVICE_WAKE || !pci_dev)
+		return;
+
+	if (!pci_dev->pm_cap || !pci_dev->pme_support
+	     || pci_check_pme_status(pci_dev)) {
 		if (pci_dev->pme_poll)
 			pci_dev->pme_poll = false;
 
 		pci_wakeup_event(pci_dev);
-		pci_check_pme_status(pci_dev);
 		pm_runtime_resume(&pci_dev->dev);
-		if (pci_dev->subordinate)
-			pci_pme_wakeup_bus(pci_dev->subordinate);
 	}
+
+	if (pci_dev->subordinate)
+		pci_pme_wakeup_bus(pci_dev->subordinate);
 }
 
 /**