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>

1 files changed, 44 insertions, 0 deletions

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 2d14f4ae6c01..e255341682c8 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -107,6 +107,50 @@ void device_pm_remove(struct device *dev)
 }
 
 /**
+ *      device_pm_move_before - move device in dpm_list
+ *      @deva:  Device to move in dpm_list
+ *      @devb:  Device @deva should come before
+ */
+void device_pm_move_before(struct device *deva, struct device *devb)
+{
+        pr_debug("PM: Moving %s:%s before %s:%s\n",
+                 deva->bus ? deva->bus->name : "No Bus",
+                 kobject_name(&deva->kobj),
+                 devb->bus ? devb->bus->name : "No Bus",
+                 kobject_name(&devb->kobj));
+        /* Delete deva from dpm_list and reinsert before devb. */
+        list_move_tail(&deva->power.entry, &devb->power.entry);
+}
+
+/**
+ *      device_pm_move_after - move device in dpm_list
+ *      @deva:  Device to move in dpm_list
+ *      @devb:  Device @deva should come after
+ */
+void device_pm_move_after(struct device *deva, struct device *devb)
+{
+        pr_debug("PM: Moving %s:%s after %s:%s\n",
+                 deva->bus ? deva->bus->name : "No Bus",
+                 kobject_name(&deva->kobj),
+                 devb->bus ? devb->bus->name : "No Bus",
+                 kobject_name(&devb->kobj));
+        /* Delete deva from dpm_list and reinsert after devb. */
+        list_move(&deva->power.entry, &devb->power.entry);
+}
+
+/**
+ *      device_pm_move_last - move device to end of dpm_list
+ *      @dev:   Device to move in dpm_list
+ */
+void device_pm_move_last(struct device *dev)
+{
+        pr_debug("PM: Moving %s:%s to end of list\n",
+                 dev->bus ? dev->bus->name : "No Bus",
+                 kobject_name(&dev->kobj));
+        list_move_tail(&dev->power.entry, &dpm_list);
+}
+
+/**
  *      pm_op - execute the PM operation appropiate for given PM event
  *      @dev:   Device.
  *      @ops:   PM operations to choose from.