PCI / PM: Skip bridges in pci_enable_wake()

PCI bridges only have a reason to generate wakeup signals on behalf
of devices below them, so avoid preparing bridges for wakeup directly
in pci_enable_wake().

Also drop the pci_has_subordinate() check from pci_pm_default_resume()
as this will be done by pci_enable_wake() itself now.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/pci-driver.c

@@ -647,9 +647,7 @@ static int pci_legacy_resume(struct device *dev)
 static void pci_pm_default_resume(struct pci_dev *pci_dev)
 {
 	pci_fixup_device(pci_fixup_resume, pci_dev);
-
-	if (!pci_has_subordinate(pci_dev))
-		pci_enable_wake(pci_dev, PCI_D0, false);
+	pci_enable_wake(pci_dev, PCI_D0, false);
 }
 
 static void pci_pm_default_suspend(struct pci_dev *pci_dev)

drivers/pci/pci.c

@@ -1912,6 +1912,13 @@ int pci_enable_wake(struct pci_dev *dev, pci_power_t state, bool enable)
 {
 	int ret = 0;
 
+	/*
+	 * Bridges can only signal wakeup on behalf of subordinate devices,
+	 * but that is set up elsewhere, so skip them.
+	 */
+	if (pci_has_subordinate(dev))
+		return 0;
+
 	/* Don't do the same thing twice in a row for one device. */
 	if (!!enable == !!dev->wakeup_prepared)
 		return 0;