[PATCH 1/4] ACPI / dock: Drop the hp_lock mutex from struct dock_station

["Rafael J. Wysocki" <rjw@sisk.pl>]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The only existing user of the hp_lock mutex in struct dock_station,
hotplug_dock_devices(), is always called under acpi_scan_lock and
cannot race with another instance of itself, so drop the mutex
which is not necessary.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/dock.c |    5 -----
 1 file changed, 5 deletions(-)

Index: linux-pm/drivers/acpi/dock.c
===================================================================
--- linux-pm.orig/drivers/acpi/dock.c
+++ linux-pm/drivers/acpi/dock.c
@@ -64,7 +64,6 @@ struct dock_station {
 	unsigned long last_dock_time;
 	u32 flags;
 	spinlock_t dd_lock;
-	struct mutex hp_lock;
 	struct list_head dependent_devices;
 
 	struct list_head sibling;
@@ -410,8 +409,6 @@ static void hotplug_dock_devices(struct
 {
 	struct dock_dependent_device *dd;
 
-	mutex_lock(&ds->hp_lock);
-
 	/*
 	 * First call driver specific hotplug functions
 	 */
@@ -430,7 +427,6 @@ static void hotplug_dock_devices(struct
 		else
 			dock_create_acpi_device(dd->handle);
 	}
-	mutex_unlock(&ds->hp_lock);
 }
 
 static void dock_event(struct dock_station *ds, u32 event, int num)
@@ -1004,7 +1000,6 @@ static int __init dock_add(acpi_handle h
 	dock_station->dock_device = dd;
 	dock_station->last_dock_time = jiffies - HZ;
 
-	mutex_init(&dock_station->hp_lock);
 	spin_lock_init(&dock_station->dd_lock);
 	INIT_LIST_HEAD(&dock_station->sibling);
 	ATOMIC_INIT_NOTIFIER_HEAD(&dock_notifier_list);