Merge branch 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6

* 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (50 commits)
  printk: do not mangle valid userspace syslog prefixes
  efivars: Add Documentation
  efivars: Expose efivars functionality to external drivers.
  efivars: Parameterize operations.
  efivars: Split out variable registration
  efivars: parameterize efivars
  efivars: Make efivars bin_attributes dynamic
  efivars: move efivars globals into struct efivars
  drivers:misc: ti-st: fix debugging code
  kref: Fix typo in kref documentation
  UIO: add PRUSS UIO driver support
  Fix spelling mistakes in Documentation/zh_CN/SubmittingPatches
  firmware: Fix unaligned memory accesses in dmi-sysfs
  firmware: Add documentation for /sys/firmware/dmi
  firmware: Expose DMI type 15 System Event Log
  firmware: Break out system_event_log in dmi-sysfs
  firmware: Basic dmi-sysfs support
  firmware: Add DMI entry types to the headers
  Driver core: convert platform_{get,set}_drvdata to static inline functions
  Translate linux-2.6/Documentation/magic-number.txt into Chinese
  ...

1 files changed, 46 insertions, 19 deletions

diff --git a/drivers/base/sys.c b/drivers/base/sys.c
index 1667aaf..f6fb547 100644
--- a/drivers/base/sys.c
+++ b/drivers/base/sys.c
@@ -166,6 +166,36 @@ EXPORT_SYMBOL_GPL(sysdev_class_unregister);
 
 static DEFINE_MUTEX(sysdev_drivers_lock);
 
+/*
+ * @dev != NULL means that we're unwinding because some drv->add()
+ * failed for some reason. You need to grab sysdev_drivers_lock before
+ * calling this.
+ */
+static void __sysdev_driver_remove(struct sysdev_class *cls,
+				   struct sysdev_driver *drv,
+				   struct sys_device *from_dev)
+{
+	struct sys_device *dev = from_dev;
+
+	list_del_init(&drv->entry);
+	if (!cls)
+		return;
+
+	if (!drv->remove)
+		goto kset_put;
+
+	if (dev)
+		list_for_each_entry_continue_reverse(dev, &cls->kset.list,
+						     kobj.entry)
+			drv->remove(dev);
+	else
+		list_for_each_entry(dev, &cls->kset.list, kobj.entry)
+			drv->remove(dev);
+
+kset_put:
+	kset_put(&cls->kset);
+}
+
 /**
  *	sysdev_driver_register - Register auxillary driver
  *	@cls:	Device class driver belongs to.
@@ -175,14 +205,14 @@ static DEFINE_MUTEX(sysdev_drivers_lock);
  *	called on each operation on devices of that class. The refcount
  *	of @cls is incremented.
  */
-
 int sysdev_driver_register(struct sysdev_class *cls, struct sysdev_driver *drv)
 {
+	struct sys_device *dev = NULL;
 	int err = 0;
 
 	if (!cls) {
-		WARN(1, KERN_WARNING "sysdev: invalid class passed to "
-			"sysdev_driver_register!\n");
+		WARN(1, KERN_WARNING "sysdev: invalid class passed to %s!\n",
+			__func__);
 		return -EINVAL;
 	}
 
@@ -198,19 +228,27 @@ int sysdev_driver_register(struct sysdev_class *cls, struct sysdev_driver *drv)
 
 		/* If devices of this class already exist, tell the driver */
 		if (drv->add) {
-			struct sys_device *dev;
-			list_for_each_entry(dev, &cls->kset.list, kobj.entry)
-				drv->add(dev);
+			list_for_each_entry(dev, &cls->kset.list, kobj.entry) {
+				err = drv->add(dev);
+				if (err)
+					goto unwind;
+			}
 		}
 	} else {
 		err = -EINVAL;
 		WARN(1, KERN_ERR "%s: invalid device class\n", __func__);
 	}
+
+	goto unlock;
+
+unwind:
+	__sysdev_driver_remove(cls, drv, dev);
+
+unlock:
 	mutex_unlock(&sysdev_drivers_lock);
 	return err;
 }
 
-
 /**
  *	sysdev_driver_unregister - Remove an auxillary driver.
  *	@cls:	Class driver belongs to.
@@ -220,23 +258,12 @@ void sysdev_driver_unregister(struct sysdev_class *cls,
 			      struct sysdev_driver *drv)
 {
 	mutex_lock(&sysdev_drivers_lock);
-	list_del_init(&drv->entry);
-	if (cls) {
-		if (drv->remove) {
-			struct sys_device *dev;
-			list_for_each_entry(dev, &cls->kset.list, kobj.entry)
-				drv->remove(dev);
-		}
-		kset_put(&cls->kset);
-	}
+	__sysdev_driver_remove(cls, drv, NULL);
 	mutex_unlock(&sysdev_drivers_lock);
 }
-
 EXPORT_SYMBOL_GPL(sysdev_driver_register);
 EXPORT_SYMBOL_GPL(sysdev_driver_unregister);
 
-
-
 /**
  *	sysdev_register - add a system device to the tree
  *	@sysdev:	device in question