[PATCH 24/46] Input: serio - do not touch bus's rwsem

Greg Kroah-Hartman
2007-04-27T18:58:28Z

From: Dmitry Torokhov <dtor@insightbb.com>

The subsystem rwsem is not used by the driver core at all, so there is
no point in trying to access it.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/input/serio/serio.c | 41 +++++++++++++++--------------------------
1 files changed, 15 insertions(+), 26 deletions(-)

diff --git a/drivers/input/serio/serio.c b/drivers/input/serio/serio.c
index a15e531..5895202 100644
--- a/drivers/input/serio/serio.c
+++ b/drivers/input/serio/serio.c
@@ -115,18 +115,18 @@ static int serio_match_port(const struct serio_device_id *ids, struct serio *ser
* Basic serio -> driver core mappings
*/

-static void serio_bind_driver(struct serio *serio, struct serio_driver *drv)
+static int serio_bind_driver(struct serio *serio, struct serio_driver *drv)
{
int error;

- down_write(&serio_bus.subsys.rwsem);
-
if (serio_match_port(drv->id_table, serio)) {
+
serio->dev.driver = &drv->driver;
if (serio_connect_driver(serio, drv)) {
serio->dev.driver = NULL;
- goto out;
+ return -ENODEV;
}
+
error = device_bind_driver(&serio->dev);
if (error) {
printk(KERN_WARNING
@@ -136,31 +136,21 @@ static void serio_bind_driver(struct serio *serio, struct serio_driver *drv)
drv->description, error);
serio_disconnect_driver(serio);
serio->dev.driver = NULL;
- goto out;
+ return error;
}
}
- out:
- up_write(&serio_bus.subsys.rwsem);
-}
-
-static void serio_release_driver(struct serio *serio)
-{
- down_write(&serio_bus.subsys.rwsem);
- device_release_driver(&serio->dev);
- up_write(&serio_bus.subsys.rwsem);
+ return 0;
}

static void serio_find_driver(struct serio *serio)
{
int error;

- down_write(&serio_bus.subsys.rwsem);
error = device_attach(&serio->dev);
if (error < 0)
printk(KERN_WARNING
"serio: device_attach() failed for %s (%s), error: %d\n",
serio->phys, serio->name, error);
- up_write(&serio_bus.subsys.rwsem);
}

@@ -470,13 +460,12 @@ static ssize_t serio_rebind_driver(struct device *dev, struct device_attribute *
{
struct serio *serio = to_serio_port(dev);
struct device_driver *drv;
- int retval;
+ int error;

- retval = mutex_lock_interruptible(&serio_mutex);
- if (retval)
- return retval;
+ error = mutex_lock_interruptible(&serio_mutex);
+ if (error)
+ return error;

- retval = count;
if (!strncmp(buf, "none", count)) {
serio_disconnect_port(serio);
} else if (!strncmp(buf, "reconnect", count)) {
@@ -486,15 +475,15 @@ static ssize_t serio_rebind_driver(struct device *dev, struct device_attribute *
serio_find_driver(serio);
} else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
serio_disconnect_port(serio);
- serio_bind_driver(serio, to_serio_driver(drv));
+ error = serio_bind_driver(serio, to_serio_driver(drv));
put_driver(drv);
} else {
- retval = -EINVAL;
+ error = -EINVAL;
}

mutex_unlock(&serio_mutex);

- return retval;
+ return error ? error : count;
}

static ssize_t serio_show_bind_mode(struct device *dev, struct device_attribute *attr, char *buf)
@@ -665,7 +654,7 @@ static void serio_disconnect_port(struct serio *serio)
do {
parent = s->parent;

- serio_release_driver(s);
+ device_release_driver(&s->dev);
serio_destroy_port(s);
} while ((s = parent) != serio);
}
@@ -673,7 +662,7 @@ static void serio_disconnect_port(struct serio *serio)
/*
* Ok, no children left, now disconnect this port
*/
- serio_release_driver(serio);
+ device_release_driver(&serio->dev);
}

void serio_rescan(struct serio *serio)
--
1.5.1.2