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    Subject[patch 23/28] 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>
    LKML-Reference: <1255175172-2666-1-git-send-email-vince@simtec.co.uk>
    Cc: Jean Delvare <khali@linux-fr.org>
    Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
    ---
    drivers/i2c/i2c-dev.c | 22 ++++++----------------
    1 file changed, 6 insertions(+), 16 deletions(-)

    Index: linux-2.6-tip/drivers/i2c/i2c-dev.c
    ===================================================================
    --- linux-2.6-tip.orig/drivers/i2c/i2c-dev.c
    +++ linux-2.6-tip/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 *ino
    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 *ino
    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 *ino
    client->adapter = adap;
    file->private_data = client;

    -out:
    - unlock_kernel();
    - return ret;
    + return 0;
    }

    static int i2cdev_release(struct inode *inode, struct file *file)



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