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authorVincent Sanders <vince@simtec.co.uk>2009-12-06 17:06:26 +0100
committerJean Delvare <khali@linux-fr.org>2009-12-06 17:06:26 +0100
commit9669f54194b4df34c96478d696d9ba2b977545f5 (patch)
tree395bf1b080dedf018c12d69398853878f882d0d5 /drivers/i2c
parentc2e90e9b6835d71cbadd42fe5b38704acaccf8aa (diff)
downloadlwn-9669f54194b4df34c96478d696d9ba2b977545f5.tar.gz
lwn-9669f54194b4df34c96478d696d9ba2b977545f5.zip
i2c: Remove big kernel lock from i2cdev_open
The BKL is held over a kmalloc so cannot protect anything beyond that. The two calls before the kmalloc have their own locking. Improve device open function by removing the now unnecessary ret variable Signed-off-by: Vincent Sanders <vince@simtec.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jean Delvare <khali@linux-fr.org>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/i2c-dev.c22
1 files changed, 6 insertions, 16 deletions
diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index 7e13d2df9af3..f4110aa49600 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -34,7 +34,6 @@
#include <linux/list.h>
#include <linux/i2c.h>
#include <linux/i2c-dev.h>
-#include <linux/smp_lock.h>
#include <linux/jiffies.h>
#include <asm/uaccess.h>
@@ -445,20 +444,14 @@ static int i2cdev_open(struct inode *inode, struct file *file)
struct i2c_client *client;
struct i2c_adapter *adap;
struct i2c_dev *i2c_dev;
- int ret = 0;
- lock_kernel();
i2c_dev = i2c_dev_get_by_minor(minor);
- if (!i2c_dev) {
- ret = -ENODEV;
- goto out;
- }
+ if (!i2c_dev)
+ return -ENODEV;
adap = i2c_get_adapter(i2c_dev->adap->nr);
- if (!adap) {
- ret = -ENODEV;
- goto out;
- }
+ if (!adap)
+ return -ENODEV;
/* This creates an anonymous i2c_client, which may later be
* pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE.
@@ -470,8 +463,7 @@ static int i2cdev_open(struct inode *inode, struct file *file)
client = kzalloc(sizeof(*client), GFP_KERNEL);
if (!client) {
i2c_put_adapter(adap);
- ret = -ENOMEM;
- goto out;
+ return -ENOMEM;
}
snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr);
client->driver = &i2cdev_driver;
@@ -479,9 +471,7 @@ static int i2cdev_open(struct inode *inode, struct file *file)
client->adapter = adap;
file->private_data = client;
-out:
- unlock_kernel();
- return ret;
+ return 0;
}
static int i2cdev_release(struct inode *inode, struct file *file)