[PATCH] usbcore: Don't call device_release_driver recursively

This patch fixes usb_driver_release_interface() to make it avoid calling
device_release_driver() recursively, i.e., when invoked from within the
disconnect routine for the same device.  The patch applies to your
"driver" tree.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 66678763c24d..a3c42203213a 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -322,9 +322,15 @@ void usb_driver_release_interface(struct usb_driver *driver,
         if (!dev->driver || dev->driver != &driver->driver)
                 return;
 
-        /* don't disconnect from disconnect(), or before dev_add() */
-        if (!klist_node_attached(&dev->knode_driver) && !klist_node_attached(&dev->knode_bus))
+        /* don't release from within disconnect() */
+        if (iface->condition != USB_INTERFACE_BOUND)
+                return;
+
+        /* release only after device_add() */
+        if (klist_node_attached(&dev->knode_bus)) {
+                iface->condition = USB_INTERFACE_UNBINDING;
                 device_release_driver(dev);
+        }
 
         dev->driver = NULL;
         usb_set_intfdata(iface, NULL);