2022-12-05 08:55:24

by ye.xingchen

Subject: [PATCH linux-next] backlight: use sysfs_emit() to instead of scnprintf()

From: ye xingchen <[email protected]>

Follow the advice of the Documentation/filesystems/sysfs.rst and show()
should only use sysfs_emit() or sysfs_emit_at() when formatting the
value to be returned to user space.

Signed-off-by: ye xingchen <[email protected]>
---
drivers/video/backlight/lm3533_bl.c | 10 +++++-----
drivers/video/backlight/lp855x_bl.c | 4 ++--
drivers/video/backlight/lp8788_bl.c | 2 +-
3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/video/backlight/lm3533_bl.c b/drivers/video/backlight/lm3533_bl.c
index 1df1b6643c0b..5e2ce9285245 100644
--- a/drivers/video/backlight/lm3533_bl.c
+++ b/drivers/video/backlight/lm3533_bl.c
@@ -66,7 +66,7 @@ static ssize_t show_id(struct device *dev,
{
struct lm3533_bl *bl = dev_get_drvdata(dev);

- return scnprintf(buf, PAGE_SIZE, "%d\n", bl->id);
+ return sysfs_emit(buf, "%d\n", bl->id);
}

static ssize_t show_als_channel(struct device *dev,
@@ -75,7 +75,7 @@ static ssize_t show_als_channel(struct device *dev,
struct lm3533_bl *bl = dev_get_drvdata(dev);
unsigned channel = lm3533_bl_get_ctrlbank_id(bl);

- return scnprintf(buf, PAGE_SIZE, "%u\n", channel);
+ return sysfs_emit(buf, "%u\n", channel);
}

static ssize_t show_als_en(struct device *dev,
@@ -95,7 +95,7 @@ static ssize_t show_als_en(struct device *dev,
mask = 1 << (2 * ctrlbank);
enable = val & mask;

- return scnprintf(buf, PAGE_SIZE, "%d\n", enable);
+ return sysfs_emit(buf, "%d\n", enable);
}

static ssize_t store_als_en(struct device *dev,
@@ -147,7 +147,7 @@ static ssize_t show_linear(struct device *dev,
else
linear = 0;

- return scnprintf(buf, PAGE_SIZE, "%x\n", linear);
+ return sysfs_emit(buf, "%x\n", linear);
}

static ssize_t store_linear(struct device *dev,
@@ -190,7 +190,7 @@ static ssize_t show_pwm(struct device *dev,
if (ret)
return ret;

- return scnprintf(buf, PAGE_SIZE, "%u\n", val);
+ return sysfs_emit(buf, "%u\n", val);
}

static ssize_t store_pwm(struct device *dev,
diff --git a/drivers/video/backlight/lp855x_bl.c b/drivers/video/backlight/lp855x_bl.c
index bd0bdeae23a4..fafc1a9e76ef 100644
--- a/drivers/video/backlight/lp855x_bl.c
+++ b/drivers/video/backlight/lp855x_bl.c
@@ -293,7 +293,7 @@ static ssize_t lp855x_get_chip_id(struct device *dev,
{
struct lp855x *lp = dev_get_drvdata(dev);

- return scnprintf(buf, PAGE_SIZE, "%s\n", lp->chipname);
+ return sysfs_emit(buf, "%s\n", lp->chipname);
}

static ssize_t lp855x_get_bl_ctl_mode(struct device *dev,
@@ -307,7 +307,7 @@ static ssize_t lp855x_get_bl_ctl_mode(struct device *dev,
else if (lp->mode == REGISTER_BASED)
strmode = "register based";

- return scnprintf(buf, PAGE_SIZE, "%s\n", strmode);
+ return sysfs_emit(buf, "%s\n", strmode);
}

static DEVICE_ATTR(chip_id, S_IRUGO, lp855x_get_chip_id, NULL);
diff --git a/drivers/video/backlight/lp8788_bl.c b/drivers/video/backlight/lp8788_bl.c
index ba42f3fe0c73..00d79c0cfee9 100644
--- a/drivers/video/backlight/lp8788_bl.c
+++ b/drivers/video/backlight/lp8788_bl.c
@@ -240,7 +240,7 @@ static ssize_t lp8788_get_bl_ctl_mode(struct device *dev,
else
strmode = "Invalid mode";

- return scnprintf(buf, PAGE_SIZE, "%s\n", strmode);
+ return sysfs_emit(buf, "%s\n", strmode);
}

static DEVICE_ATTR(bl_ctl_mode, S_IRUGO, lp8788_get_bl_ctl_mode, NULL);
--
2.25.1

2022-12-09 13:29:57

by Daniel Thompson

Subject: Re: [PATCH linux-next] backlight: use sysfs_emit() to instead of scnprintf()

On Mon, Dec 05, 2022 at 03:56:47PM +0800, [email protected] wrote:
> Subject: [PATCH linux-next] backlight: use sysfs_emit() to instead of
> scnprintf()

Isn't this a v2?

(this isn't just a "nice to have"... I ended up delaying review for
several days until I had time to look up where I had seen these changes
before)


> From: ye xingchen <[email protected]>
>
> Follow the advice of the Documentation/filesystems/sysfs.rst and show()
> should only use sysfs_emit() or sysfs_emit_at() when formatting the
> value to be returned to user space.
>
> Signed-off-by: ye xingchen <[email protected]>

Reviewed-by: Daniel Thompson <[email protected]>


Daniel.

2023-01-04 16:24:36

by Lee Jones

Subject: Re: [PATCH linux-next] backlight: use sysfs_emit() to instead of scnprintf()

On Mon, 05 Dec 2022, [email protected] wrote:

> From: ye xingchen <[email protected]>
>
> Follow the advice of the Documentation/filesystems/sysfs.rst and show()
> should only use sysfs_emit() or sysfs_emit_at() when formatting the
> value to be returned to user space.
>
> Signed-off-by: ye xingchen <[email protected]>
> ---
> drivers/video/backlight/lm3533_bl.c | 10 +++++-----
> drivers/video/backlight/lp855x_bl.c | 4 ++--
> drivers/video/backlight/lp8788_bl.c | 2 +-
> 3 files changed, 8 insertions(+), 8 deletions(-)

Is this v3?

--
Lee Jones [李琼斯]