[PATCH 2/2] serio: lockdep annotation for ps2dev->cmd_mutex and serio->lock

From: Peter Zijlstra
Date: Tue Sep 26 2006 - 07:46:30 EST


Based ideas from Jiri Kosina, this patch tracks the nesting depth
and uses the new lockdep_set_class_and_subclass() annotation to store
this information in the lock objects.

Signed-of-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
---
drivers/input/serio/libps2.c | 4 ++++
drivers/input/serio/serio.c | 9 ++++++++-
include/linux/serio.h | 1 +
3 files changed, 13 insertions(+), 1 deletion(-)

Index: linux-2.6-mm/drivers/input/serio/libps2.c
===================================================================
--- linux-2.6-mm.orig/drivers/input/serio/libps2.c 2006-09-26 10:25:22.000000000 +0200
+++ linux-2.6-mm/drivers/input/serio/libps2.c 2006-09-26 10:34:49.000000000 +0200
@@ -280,6 +280,8 @@ int ps2_schedule_command(struct ps2dev *
return 0;
}

+static struct lock_class_key ps2_mutex_key;
+
/*
* ps2_init() initializes ps2dev structure
*/
@@ -287,6 +289,8 @@ int ps2_schedule_command(struct ps2dev *
void ps2_init(struct ps2dev *ps2dev, struct serio *serio)
{
mutex_init(&ps2dev->cmd_mutex);
+ lockdep_set_class_and_subclass(&ps2dev->cmd_mutex, &ps2_mutex_key,
+ serio->depth);
init_waitqueue_head(&ps2dev->wait);
ps2dev->serio = serio;
}
Index: linux-2.6-mm/drivers/input/serio/serio.c
===================================================================
--- linux-2.6-mm.orig/drivers/input/serio/serio.c 2006-09-26 10:25:22.000000000 +0200
+++ linux-2.6-mm/drivers/input/serio/serio.c 2006-09-26 10:34:04.000000000 +0200
@@ -521,6 +521,8 @@ static void serio_release_port(struct de
module_put(THIS_MODULE);
}

+static struct lock_class_key serio_lock_key;
+
/*
* Prepare serio port for registration.
*/
@@ -538,8 +540,13 @@ static void serio_init_port(struct serio
"serio%ld", (long)atomic_inc_return(&serio_no) - 1);
serio->dev.bus = &serio_bus;
serio->dev.release = serio_release_port;
- if (serio->parent)
+ if (serio->parent) {
serio->dev.parent = &serio->parent->dev;
+ serio->depth = serio->parent->depth + 1;
+ } else
+ serio->depth = 0;
+ lockdep_set_class_and_subclass(&serio->lock, &serio_lock_key,
+ serio->depth);
}

/*
Index: linux-2.6-mm/include/linux/serio.h
===================================================================
--- linux-2.6-mm.orig/include/linux/serio.h 2006-09-26 10:25:22.000000000 +0200
+++ linux-2.6-mm/include/linux/serio.h 2006-09-26 10:34:04.000000000 +0200
@@ -41,6 +41,7 @@ struct serio {
void (*stop)(struct serio *);

struct serio *parent, *child;
+ unsigned int depth; /* level of nesting in serio hierarchy */

struct serio_driver *drv; /* accessed from interrupt, must be protected by serio->lock and serio->sem */
struct mutex drv_mutex; /* protects serio->drv so attributes can pin driver */

--

-
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