[PATCH] staging: greybus: light: use sysfs_emit() instead of sprintf()

[PATCH] staging: greybus: light: use sysfs_emit() instead of sprintf()

[ts930]

From: Park Tae-sun <ts930@dgu.ac.kr>

The sysfs documentation (Documentation/filesystems/sysfs.rst) recommends
using sysfs_emit() instead of sprintf() in sysfs show() callbacks.

Replace the remaining sprintf() calls in the fade_##__dir##_show()
macro and color_show() callback with sysfs_emit().

This follows the standard kernel practice and existing use of
sysfs_emit() in other Greybus sysfs show functions.

No functional change.

Signed-off-by: Park Tae-sun <ts930@dgu.ac.kr>
---
 drivers/staging/greybus/light.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/greybus/light.c b/drivers/staging/greybus/light.c
index cab02b5da867..2689f9a7524a 100644
--- a/drivers/staging/greybus/light.c
+++ b/drivers/staging/greybus/light.c
@@ -173,7 +173,7 @@ static ssize_t fade_##__dir##_show(struct device *dev,			\
 	struct led_classdev *cdev = dev_get_drvdata(dev);		\
 	struct gb_channel *channel = get_channel_from_cdev(cdev);	\
 									\
-	return sprintf(buf, "%u\n", channel->fade_##__dir);		\
+	return sysfs_emit(buf, "%u\n", channel->fade_##__dir);		\
 }									\
 									\
 static ssize_t fade_##__dir##_store(struct device *dev,			\
@@ -220,7 +220,7 @@ static ssize_t color_show(struct device *dev, struct device_attribute *attr,
 	struct led_classdev *cdev = dev_get_drvdata(dev);
 	struct gb_channel *channel = get_channel_from_cdev(cdev);
 
-	return sprintf(buf, "0x%08x\n", channel->color);
+	return sysfs_emit(buf, "0x%08x\n", channel->color);
 }
 
 static ssize_t color_store(struct device *dev, struct device_attribute *attr,
-- 
2.43.0

Re: [PATCH] staging: greybus: light: use sysfs_emit() instead of sprintf()

[Greg Kroah-Hartman]

On Sun, Sep 20, 2026 at 10:38:03PM +0900, ts930@naver.com wrote:
> From: Park Tae-sun <ts930@dgu.ac.kr>
> 
> The sysfs documentation (Documentation/filesystems/sysfs.rst) recommends
> using sysfs_emit() instead of sprintf() in sysfs show() callbacks.
> 
> Replace the remaining sprintf() calls in the fade_##__dir##_show()
> macro and color_show() callback with sysfs_emit().
> 
> This follows the standard kernel practice and existing use of
> sysfs_emit() in other Greybus sysfs show functions.
> 
> No functional change.

How is this different from past patches that have attempted to change
this?

thanks,

greg k-h

[PATCH] staging: greybus: light: use sysfs_emit() instead of sprintf()

[Mohit Mishra]

color_show() and fade_show callbacks use sprintf() to format sysfs output
into the page buffer. Convert them to sysfs_emit(), which is the preferred
helper for sysfs show() callbacks as it enforces page boundary checks.

Similar conversions have already been made elsewhere in this subsystem
(e.g. loopback.c, arche-platform.c).

Signed-off-by: Mohit Mishra <mishraloopmohit@gmail.com>
---
 drivers/staging/greybus/light.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/greybus/light.c b/drivers/staging/greybus/light.c
index cab02b5da867..2689f9a7524a 100644
--- a/drivers/staging/greybus/light.c
+++ b/drivers/staging/greybus/light.c
@@ -173,7 +173,7 @@ static ssize_t fade_##__dir##_show(struct device *dev,			\
 	struct led_classdev *cdev = dev_get_drvdata(dev);		\
 	struct gb_channel *channel = get_channel_from_cdev(cdev);	\
 									\
-	return sprintf(buf, "%u\n", channel->fade_##__dir);		\
+	return sysfs_emit(buf, "%u\n", channel->fade_##__dir);		\
 }									\
 									\
 static ssize_t fade_##__dir##_store(struct device *dev,			\
@@ -220,7 +220,7 @@ static ssize_t color_show(struct device *dev, struct device_attribute *attr,
 	struct led_classdev *cdev = dev_get_drvdata(dev);
 	struct gb_channel *channel = get_channel_from_cdev(cdev);
 
-	return sprintf(buf, "0x%08x\n", channel->color);
+	return sysfs_emit(buf, "0x%08x\n", channel->color);
 }
 
 static ssize_t color_store(struct device *dev, struct device_attribute *attr,
-- 
2.43.0