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>

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)