Merge branch 'master' into mm-hotfixes-stable

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 2633acde7ac1..bbab424b0d55 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -6038,6 +6038,11 @@ re_enumerate:
  * the reset is over (using their post_reset method).
  *
  * Return: The same as for usb_reset_and_verify_device().
+ * However, if a reset is already in progress (for instance, if a
+ * driver doesn't have pre_reset() or post_reset() callbacks, and while
+ * being unbound or re-bound during the ongoing reset its disconnect()
+ * or probe() routine tries to perform a second, nested reset), the
+ * routine returns -EINPROGRESS.
  *
  * Note:
  * The caller must own the device lock.  For example, it's safe to use
@@ -6071,6 +6076,10 @@ int usb_reset_device(struct usb_device *udev)
 		return -EISDIR;
 	}
 
+	if (udev->reset_in_progress)
+		return -EINPROGRESS;
+	udev->reset_in_progress = 1;
+
 	port_dev = hub->ports[udev->portnum - 1];
 
 	/*
@@ -6135,6 +6144,7 @@ int usb_reset_device(struct usb_device *udev)
 
 	usb_autosuspend_device(udev);
 	memalloc_noio_restore(noio_flag);
+	udev->reset_in_progress = 0;
 	return ret;
 }
 EXPORT_SYMBOL_GPL(usb_reset_device);