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

From: Rafael J. Wysocki
Date: Fri Jun 28 2013 - 15:39:19 EST


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

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@xxxxxxxxx>
---
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);

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