[BUGFIX 5/9] ACPI, DOCK: kill redundant spin lock in dock device object

From: Jiang Liu
Date: Thu Jun 13 2013 - 12:35:48 EST


All dock device related data structures are created during driver
initialization, so kill the redundant spin lock in dock device object.

Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
Cc: Shaohua Li <shaohua.li@xxxxxxxxx>
Cc: Len Brown <lenb@xxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rjw@xxxxxxx>
Cc: linux-acpi@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
drivers/acpi/dock.c | 15 +++------------
1 file changed, 3 insertions(+), 12 deletions(-)

diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
index 8e578aa..cd2d5df 100644
--- a/drivers/acpi/dock.c
+++ b/drivers/acpi/dock.c
@@ -57,7 +57,6 @@ struct dock_station {
acpi_handle handle;
unsigned long last_dock_time;
u32 flags;
- spinlock_t dd_lock;
struct mutex hp_lock;
struct task_struct *owner;
struct list_head dependent_devices;
@@ -107,10 +106,7 @@ add_dock_dependent_device(struct dock_station *ds, acpi_handle handle)
dd->handle = handle;
INIT_LIST_HEAD(&dd->list);
INIT_LIST_HEAD(&dd->hotplug_list);
-
- spin_lock(&ds->dd_lock);
list_add_tail(&dd->list, &ds->dependent_devices);
- spin_unlock(&ds->dd_lock);

return 0;
}
@@ -168,14 +164,10 @@ 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;
}

@@ -964,7 +956,6 @@ 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->hotplug_devices);
INIT_LIST_HEAD(&dock_station->dependent_devices);
--
1.8.1.2

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