Driver core: Fix device_move() vs. dpm list ordering, v2

dpm_list currently relies on the fact that child devices will
be registered after their parents to get a correct suspend
order. Using device_move() however destroys this assumption, as
an already registered device may be moved under a newly registered
one.

This patch adds a new argument to device_move(), allowing callers
to specify how dpm_list should be adapted.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 13 insertions, 1 deletions

diff --git a/include/linux/device.h b/include/linux/device.h
index 914c1016dd8f..f98d0cfb4f81 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -494,7 +494,8 @@ extern int device_for_each_child(struct device *dev, void *data,
 extern struct device *device_find_child(struct device *dev, void *data,
                                 int (*match)(struct device *dev, void *data));
 extern int device_rename(struct device *dev, char *new_name);
-extern int device_move(struct device *dev, struct device *new_parent);
+extern int device_move(struct device *dev, struct device *new_parent,
+                       enum dpm_order dpm_order);
 
 /*
  * Root device objects for grouping under /sys/devices
diff --git a/include/linux/pm.h b/include/linux/pm.h
index 24ba5f67b3a3..1d4e2d289821 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -400,6 +400,9 @@ extern void __suspend_report_result(const char *function, void *fn, int ret);
 
 #else /* !CONFIG_PM_SLEEP */
 
+#define device_pm_lock() do {} while (0)
+#define device_pm_unlock() do {} while (0)
+
 static inline int device_suspend(pm_message_t state)
 {
         return 0;
@@ -409,6 +412,14 @@ static inline int device_suspend(pm_message_t state)
 
 #endif /* !CONFIG_PM_SLEEP */
 
+/* How to reorder dpm_list after device_move() */
+enum dpm_order {
+        DPM_ORDER_NONE,
+        DPM_ORDER_DEV_AFTER_PARENT,
+        DPM_ORDER_PARENT_BEFORE_DEV,
+        DPM_ORDER_DEV_LAST,
+};
+
 /*
  * Global Power Management flags
  * Used to keep APM and ACPI from both being active