Merge tag 'for-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb...

[karo-tx-linux.git] / drivers / base / core.c

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 4a67cc0c8b37aaeeec97e27eef04752a52504d1a..74dda4f697f92d772355f37c0a82553e7827119d 100644 (file)
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -632,6 +632,11 @@ static void klist_children_put(struct klist_node *n)
  * may be used for reference counting of @dev after calling this
  * function.
  *
+ * All fields in @dev must be initialized by the caller to 0, except
+ * for those explicitly set to some other value.  The simplest
+ * approach is to use kzalloc() to allocate the structure containing
+ * @dev.
+ *
  * NOTE: Use put_device() to give up your reference instead of freeing
  * @dev directly once you have called this function.
  */
@@ -930,6 +935,13 @@ int device_private_init(struct device *dev)
  * to the global and sibling lists for the device, then
  * adds it to the other relevant subsystems of the driver model.
  *
+ * Do not call this routine or device_register() more than once for
+ * any device structure.  The driver model core is not designed to work
+ * with devices that get unregistered and then spring back to life.
+ * (Among other things, it's very hard to guarantee that all references
+ * to the previous incarnation of @dev have been dropped.)  Allocate
+ * and register a fresh new struct device instead.
+ *
  * NOTE: _Never_ directly free @dev after calling this function, even
  * if it returned an error! Always use put_device() to give up your
  * reference instead.
@@ -1022,7 +1034,7 @@ int device_add(struct device *dev)
        device_pm_add(dev);
 
        /* Notify clients of device addition.  This call must come
-        * after dpm_sysf_add() and before kobject_uevent().
+        * after dpm_sysfs_add() and before kobject_uevent().
         */
        if (dev->bus)
                blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
@@ -1090,6 +1102,9 @@ name_error:
  * have a clearly defined need to use and refcount the device
  * before it is added to the hierarchy.
  *
+ * For more information, see the kerneldoc for device_initialize()
+ * and device_add().
+ *
  * NOTE: _Never_ directly free @dev after calling this function, even
  * if it returned an error! Always use put_device() to give up the
  * reference initialized in this function instead.