Driver Core: add ability for class_find_device to start in middle of list

This mirrors the functionality that driver_find_device has as well.

We add a start variable, and all callers of the function are fixed up at
the same time.

The block layer will be using this new functionality in a follow-on
patch.


Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 13 insertions, 9 deletions

diff --git a/drivers/base/class.c b/drivers/base/class.c
index 2eb7048003a8..3918d0e432d4 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -302,6 +302,7 @@ EXPORT_SYMBOL_GPL(class_for_each_device);
 /**
  * class_find_device - device iterator for locating a particular device
  * @class: the class we're iterating
+ * @start: Device to begin with
  * @data: data for the match function
  * @match: function to check device
  *
@@ -319,8 +320,9 @@ EXPORT_SYMBOL_GPL(class_for_each_device);
  * re-acquired in @match, otherwise it will self-deadlocking. For
  * example, calls to add or remove class members would be verboten.
  */
-struct device *class_find_device(struct class *class, void *data,
-                                   int (*match)(struct device *, void *))
+struct device *class_find_device(struct class *class, struct device *start,
+                                 void *data,
+                                 int (*match)(struct device *, void *))
 {
         struct device *dev;
         int found = 0;
@@ -330,15 +332,17 @@ struct device *class_find_device(struct class *class, void *data,
 
         down(&class->sem);
         list_for_each_entry(dev, &class->devices, node) {
+                if (start) {
+                        if (start == dev)
+                                start = NULL;
+                        continue;
+                }
                 dev = get_device(dev);
-                if (dev) {
-                        if (match(dev, data)) {
-                                found = 1;
-                                break;
-                        } else
-                                put_device(dev);
-                } else
+                if (match(dev, data)) {
+                        found = 1;
                         break;
+                } else
+                        put_device(dev);
         }
         up(&class->sem);