ACPI / dock: drop redundant spin lock in dock station object

All dock station objects are created during initialization and
don't change at runtime, so drop the redundant spin lock from
struct dock_station.

[rjw: Changelog]
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
index c36de86..750f958 100644 (file)
--- a/drivers/acpi/dock.c
+++ b/drivers/acpi/dock.c
@@ -63,7 +63,6 @@ struct dock_station {
        acpi_handle handle;
        unsigned long last_dock_time;
        u32 flags;
-       spinlock_t dd_lock;
        struct mutex hp_lock;
        struct list_head dependent_devices;
 
@@ -112,10 +111,7 @@ add_dock_dependent_device(struct dock_station *ds, acpi_handle handle)
 
        dd->handle = handle;
        INIT_LIST_HEAD(&dd->list);
-
-       spin_lock(&ds->dd_lock);
        list_add_tail(&dd->list, &ds->dependent_devices);
-       spin_unlock(&ds->dd_lock);
 
        return 0;
 }
@@ -220,14 +216,10 @@ find_dock_dependent_device(struct dock_station *ds, acpi_handle handle)
 {
        struct dock_dependent_device *dd;
 
-       spin_lock(&ds->dd_lock);
-       list_for_each_entry(dd, &ds->dependent_devices, list) {
-               if (handle == dd->handle) {
-                       spin_unlock(&ds->dd_lock);
+       list_for_each_entry(dd, &ds->dependent_devices, list)
+               if (handle == dd->handle)
                        return dd;
-               }
-       }
-       spin_unlock(&ds->dd_lock);
+
        return NULL;
 }
 
@@ -1005,7 +997,6 @@ static int __init dock_add(acpi_handle handle)
        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);
        INIT_LIST_HEAD(&dock_station->dependent_devices);