[PATCH 25/46] Input: gameport - do not touch bus's rwsem

Greg Kroah-Hartman
2007-04-27T18:59:15Z

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/gameport/gameport.c | 39 ++++++++++++------------------------
1 files changed, 13 insertions(+), 26 deletions(-)

diff --git a/drivers/input/gameport/gameport.c b/drivers/input/gameport/gameport.c
index a00fe47..bd686a2 100644
--- a/drivers/input/gameport/gameport.c
+++ b/drivers/input/gameport/gameport.c
@@ -190,16 +190,14 @@ static void gameport_run_poll_handler(unsigned long d)
* Basic gameport -> driver core mappings
*/

-static void gameport_bind_driver(struct gameport *gameport, struct gameport_driver *drv)
+static int gameport_bind_driver(struct gameport *gameport, struct gameport_driver *drv)
{
int error;

- down_write(&gameport_bus.subsys.rwsem);
-
gameport->dev.driver = &drv->driver;
if (drv->connect(gameport, drv)) {
gameport->dev.driver = NULL;
- goto out;
+ return -ENODEV;
}

error = device_bind_driver(&gameport->dev);
@@ -211,31 +209,21 @@ static void gameport_bind_driver(struct gameport *gameport, struct gameport_driv
drv->description, error);
drv->disconnect(gameport);
gameport->dev.driver = NULL;
- goto out;
+ return error;
}

- out:
- up_write(&gameport_bus.subsys.rwsem);
-}
-
-static void gameport_release_driver(struct gameport *gameport)
-{
- down_write(&gameport_bus.subsys.rwsem);
- device_release_driver(&gameport->dev);
- up_write(&gameport_bus.subsys.rwsem);
+ return 0;
}

static void gameport_find_driver(struct gameport *gameport)
{
int error;

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

@@ -483,13 +471,12 @@ static ssize_t gameport_rebind_driver(struct device *dev, struct device_attribut
{
struct gameport *gameport = to_gameport_port(dev);
struct device_driver *drv;
- int retval;
+ int error;

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

- retval = count;
if (!strncmp(buf, "none", count)) {
gameport_disconnect_port(gameport);
} else if (!strncmp(buf, "reconnect", count)) {
@@ -499,15 +486,15 @@ static ssize_t gameport_rebind_driver(struct device *dev, struct device_attribut
gameport_find_driver(gameport);
} else if ((drv = driver_find(buf, &gameport_bus)) != NULL) {
gameport_disconnect_port(gameport);
- gameport_bind_driver(gameport, to_gameport_driver(drv));
+ error = gameport_bind_driver(gameport, to_gameport_driver(drv));
put_driver(drv);
} else {
- retval = -EINVAL;
+ error = -EINVAL;
}

mutex_unlock(&gameport_mutex);

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

static struct device_attribute gameport_device_attrs[] = {
@@ -655,7 +642,7 @@ static void gameport_disconnect_port(struct gameport *gameport)
do {
parent = s->parent;

- gameport_release_driver(s);
+ device_release_driver(&s->dev);
gameport_destroy_port(s);
} while ((s = parent) != gameport);
}
@@ -663,7 +650,7 @@ static void gameport_disconnect_port(struct gameport *gameport)
/*
* Ok, no children left, now disconnect this port
*/
- gameport_release_driver(gameport);
+ device_release_driver(&gameport->dev);
}

void gameport_rescan(struct gameport *gameport)
--
1.5.1.2