1 files changed, 14 insertions, 1 deletions

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index fa601b085eba..e3f915a24891 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -152,7 +152,11 @@ static ssize_t driver_unbind(struct device_driver *drv,
 
         dev = bus_find_device(bus, NULL, (void *)buf, driver_helper);
         if (dev && dev->driver == drv) {
+                if (dev->parent)        /* Needed for USB */
+                        down(&dev->parent->sem);
                 device_release_driver(dev);
+                if (dev->parent)
+                        up(&dev->parent->sem);
                 err = count;
         }
         put_device(dev);
@@ -175,9 +179,13 @@ static ssize_t driver_bind(struct device_driver *drv,
 
         dev = bus_find_device(bus, NULL, (void *)buf, driver_helper);
         if (dev && dev->driver == NULL) {
+                if (dev->parent)        /* Needed for USB */
+                        down(&dev->parent->sem);
                 down(&dev->sem);
                 err = driver_probe_device(drv, dev);
                 up(&dev->sem);
+                if (dev->parent)
+                        up(&dev->parent->sem);
         }
         put_device(dev);
         put_bus(bus);
@@ -484,8 +492,13 @@ void bus_remove_driver(struct device_driver * drv)
 /* Helper for bus_rescan_devices's iter */
 static int bus_rescan_devices_helper(struct device *dev, void *data)
 {
-        if (!dev->driver)
+        if (!dev->driver) {
+                if (dev->parent)        /* Needed for USB */
+                        down(&dev->parent->sem);
                 device_attach(dev);
+                if (dev->parent)
+                        up(&dev->parent->sem);
+        }
         return 0;
 }