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>

diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index 7e13d2d..f4110aa 100644 (file)
--- 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)