4 files changed, 16 insertions, 12 deletions

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index ef6183306b40..8bfd27ec73d6 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -184,10 +184,10 @@ static ssize_t unbind_store(struct device_driver *drv, const char *buf,
 
         dev = bus_find_device_by_name(bus, NULL, buf);
         if (dev && dev->driver == drv) {
-                if (dev->parent)        /* Needed for USB */
+                if (dev->parent && dev->bus->need_parent_lock)
                         device_lock(dev->parent);
                 device_release_driver(dev);
-                if (dev->parent)
+                if (dev->parent && dev->bus->need_parent_lock)
                         device_unlock(dev->parent);
                 err = count;
         }
@@ -211,12 +211,12 @@ static ssize_t bind_store(struct device_driver *drv, const char *buf,
 
         dev = bus_find_device_by_name(bus, NULL, buf);
         if (dev && dev->driver == NULL && driver_match_device(drv, dev)) {
-                if (dev->parent)        /* Needed for USB */
+                if (dev->parent && bus->need_parent_lock)
                         device_lock(dev->parent);
                 device_lock(dev);
                 err = driver_probe_device(drv, dev);
                 device_unlock(dev);
-                if (dev->parent)
+                if (dev->parent && bus->need_parent_lock)
                         device_unlock(dev->parent);
 
                 if (err > 0) {
@@ -735,10 +735,10 @@ static int __must_check bus_rescan_devices_helper(struct device *dev,
         int ret = 0;
 
         if (!dev->driver) {
-                if (dev->parent)        /* Needed for USB */
+                if (dev->parent && dev->bus->need_parent_lock)
                         device_lock(dev->parent);
                 ret = device_attach(dev);
-                if (dev->parent)
+                if (dev->parent && dev->bus->need_parent_lock)
                         device_unlock(dev->parent);
         }
         return ret < 0 ? ret : 0;
@@ -770,10 +770,10 @@ EXPORT_SYMBOL_GPL(bus_rescan_devices);
 int device_reprobe(struct device *dev)
 {
         if (dev->driver) {
-                if (dev->parent)        /* Needed for USB */
+                if (dev->parent && dev->bus->need_parent_lock)
                         device_lock(dev->parent);
                 device_release_driver(dev);
-                if (dev->parent)
+                if (dev->parent && dev->bus->need_parent_lock)
                         device_unlock(dev->parent);
         }
         return bus_rescan_devices_helper(dev, NULL);
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index c9f54089429b..7c09f73b96f3 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -817,13 +817,13 @@ static int __driver_attach(struct device *dev, void *data)
                 return ret;
         } /* ret > 0 means positive match */
 
-        if (dev->parent)        /* Needed for USB */
+        if (dev->parent && dev->bus->need_parent_lock)
                 device_lock(dev->parent);
         device_lock(dev);
         if (!dev->driver)
                 driver_probe_device(drv, dev);
         device_unlock(dev);
-        if (dev->parent)
+        if (dev->parent && dev->bus->need_parent_lock)
                 device_unlock(dev->parent);
 
         return 0;
@@ -919,7 +919,7 @@ void device_release_driver_internal(struct device *dev,
                                     struct device_driver *drv,
                                     struct device *parent)
 {
-        if (parent)
+        if (parent && dev->bus->need_parent_lock)
                 device_lock(parent);
 
         device_lock(dev);
@@ -927,7 +927,7 @@ void device_release_driver_internal(struct device *dev,
                 __device_release_driver(dev, parent);
 
         device_unlock(dev);
-        if (parent)
+        if (parent && dev->bus->need_parent_lock)
                 device_unlock(parent);
 }
 
diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 9792cedfc351..e76e95f62f76 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -1922,4 +1922,5 @@ struct bus_type usb_bus_type = {
         .name =         "usb",
         .match =        usb_device_match,
         .uevent =       usb_uevent,
+        .need_parent_lock =     true,
 };
diff --git a/include/linux/device.h b/include/linux/device.h
index 477956990f5e..beca424395dd 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -98,6 +98,8 @@ extern void bus_remove_file(struct bus_type *, struct bus_attribute *);
  * @lock_key:   Lock class key for use by the lock validator
  * @force_dma:  Assume devices on this bus should be set up by dma_configure()
  *              even if DMA capability is not explicitly described by firmware.
+ * @need_parent_lock:   When probing or removing a device on this bus, the
+ *                      device core should lock the device's parent.
  *
  * A bus is a channel between the processor and one or more devices. For the
  * purposes of the device model, all devices are connected via a bus, even if
@@ -138,6 +140,7 @@ struct bus_type {
         struct lock_class_key lock_key;
 
         bool force_dma;
+        bool need_parent_lock;
 };
 
 extern int __must_check bus_register(struct bus_type *bus);