Re: [PATCH] PM / devfreq: Add new name attribute for sysfs

[Greg KH]

On Wed, Aug 29, 2018 at 04:34:06PM +0900, Chanwoo Choi wrote:
> commit 4585fbcb5331 ("PM / devfreq: Modify the device name as devfreq(X) for
> sysfs") changed the node name to devfreq(x). After this commit, it is not
> possible to get the device name through /sys/class/devfreq/devfreq(X)/*.
> 
> Add new name attribute in order to get device name.
> 
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 4585fbcb5331 ("PM / devfreq: Modify the device name as devfreq(X) for sysfs")
> Signed-off-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
> ---
>  drivers/devfreq/devfreq.c | 11 +++++++++++
>  include/linux/devfreq.h   |  3 +++
>  2 files changed, 14 insertions(+)
> 
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index 4c49bb1330b5..2145563d5ee5 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -620,6 +620,9 @@ struct devfreq *devfreq_add_device(struct device *dev,
>  	}
>  	devfreq->max_freq = devfreq->scaling_max_freq;
> 
> +	devfreq->name = dev_name(devfreq->dev.parent);
> +	if (IS_ERR_OR_NULL(devfreq->name))
> +		return -EINVAL;
>  	dev_set_name(&devfreq->dev, "devfreq%d",
>  				atomic_inc_return(&devfreq_no));
>  	err = device_register(&devfreq->dev);
> @@ -1261,6 +1264,13 @@ static ssize_t trans_stat_show(struct device *dev,
>  }
>  static DEVICE_ATTR_RO(trans_stat);
> 
> +static ssize_t name_show(struct device *dev,
> +			struct device_attribute *attr, char *buf)
> +{
> +	return sprintf(buf, "%s\n", to_devfreq(dev)->name);
> +}
> +static DEVICE_ATTR_RO(name);

You need a new Documentation/ABI/ entry for this.

thanks,

greg k-h