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Commit 9669f541 authored by Vincent Sanders's avatar Vincent Sanders Committed by Jean Delvare
Browse files

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: default avatarVincent Sanders <vince@simtec.co.uk>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
parent c2e90e9b

drivers/i2c/i2c-dev.c

+6 −16
Original line number Diff line number Diff line
@@ -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)