Re: [PATCH] i2c: i2c-dev: Create 'name' attribute automatically

Wolfram Sang
2013-09-25T20:20:39Z

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On Sat, Aug 31, 2013 at 09:30:19AM -0700, Guenter Roeck wrote:
> The 'name' attribute is needed for all i2c-dev class devices, meaning
> it can be created automatically by pointing to it in the class data
> structure. This simplifies the code and reduces the probability for race
> conditions.

What race condition?

>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> ---
> drivers/i2c/i2c-dev.c | 32 ++++++++++++++++----------------
> 1 file changed, 16 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
> index c3ccdea..46eea02 100644
> --- a/drivers/i2c/i2c-dev.c
> +++ b/drivers/i2c/i2c-dev.c
> @@ -111,7 +111,11 @@ static ssize_t show_adapter_name(struct device *dev,
> return -ENODEV;
> return sprintf(buf, "%s\n", i2c_dev->adap->name);
> }
> -static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
> +
> +static struct device_attribute i2c_dev_attributes[] = {
> + __ATTR(name, S_IRUGO, show_adapter_name, NULL),
> + { }
> +};
>
> /* ------------------------------------------------------------------------- */
>
> @@ -538,7 +542,11 @@ static const struct file_operations i2cdev_fops = {
>
> /* ------------------------------------------------------------------------- */
>
> -static struct class *i2c_dev_class;
> +static struct class i2c_dev_class = {
> + .owner = THIS_MODULE,
> + .name = "i2c-dev",
> + .dev_attrs = i2c_dev_attributes,
> +};

Have you tried this with two instances? I don't think it will work since
class_register modifies the class struct.

Regards,

Wolfram

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