Dear Greg,

On 2018년 08월 29일 19:57, Greg KH wrote:

On Wed, Aug 29, 2018 at 04:34:06PM +0900, Chanwoo Choi wrote:

quoted

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@vger.kernel.org
Fixes: 4585fbcb5331 ("PM / devfreq: Modify the device name as devfreq(X) for sysfs")
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
---
 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 for comment. I'll.

Best Regards,
Chanwoo Choi
Samsung Electronics