--- zzzz-none-000/linux-3.10.107/drivers/xen/xen-pciback/passthrough.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/xen/xen-pciback/passthrough.c	2021-02-04 17:41:59.000000000 +0000
@@ -69,7 +69,7 @@
 }
 
 static void __xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
-					struct pci_dev *dev)
+					struct pci_dev *dev, bool lock)
 {
 	struct passthrough_dev_data *dev_data = pdev->pci_dev_data;
 	struct pci_dev_entry *dev_entry, *t;
@@ -87,8 +87,13 @@
 
 	mutex_unlock(&dev_data->lock);
 
-	if (found_dev)
+	if (found_dev) {
+		if (lock)
+			device_lock(&found_dev->dev);
 		pcistub_put_pci_dev(found_dev);
+		if (lock)
+			device_unlock(&found_dev->dev);
+	}
 }
 
 static int __xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
@@ -156,8 +161,11 @@
 	struct pci_dev_entry *dev_entry, *t;
 
 	list_for_each_entry_safe(dev_entry, t, &dev_data->dev_list, list) {
+		struct pci_dev *dev = dev_entry->dev;
 		list_del(&dev_entry->list);
-		pcistub_put_pci_dev(dev_entry->dev);
+		device_lock(&dev->dev);
+		pcistub_put_pci_dev(dev);
+		device_unlock(&dev->dev);
 		kfree(dev_entry);
 	}