Merge tag 'pci-v4.6-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI fixes from Bjorn Helgaas:
 "Since v4.5, we've WARNed during resume if a PCI device, including a
  Thunderbolt device, was added while we were suspended.  A change we
  merged for v4.6-rc1 turned that warning into a system hang.  These
  enumeration patches from Lukas Wunner fix this issue:

   - Fix BUG on device attach failure
   - Do not treat EPROBE_DEFER as device attach failure"

* tag 'pci-v4.6-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: Do not treat EPROBE_DEFER as device attach failure
  PCI: Fix BUG on device attach failure

drivers/pci/bus.c

@@ -294,7 +294,7 @@ void pci_bus_add_device(struct pci_dev *dev)
 
 	dev->match_driver = true;
 	retval = device_attach(&dev->dev);
-	if (retval < 0) {
+	if (retval < 0 && retval != -EPROBE_DEFER) {
 		dev_warn(&dev->dev, "device attach failed (%d)\n", retval);
 		pci_proc_detach_device(dev);
 		pci_remove_sysfs_dev_files(dev);
@@ -324,7 +324,9 @@ void pci_bus_add_devices(const struct pci_bus *bus)
 	}
 
 	list_for_each_entry(dev, &bus->devices, bus_list) {
-		BUG_ON(!dev->is_added);
+		/* Skip if device attach failed */
+		if (!dev->is_added)
+			continue;
 		child = dev->subordinate;
 		if (child)
 			pci_bus_add_devices(child);