[PATCH v3] video: fbdev: panel-tpo-td043mtea1: Convert sprintf() family to sysfs_emit() family

[PATCH v3] video: fbdev: panel-tpo-td043mtea1: Convert sprintf() family to sysfs_emit() family

[Li Zhijian]

Per filesystems/sysfs.rst, show() should only use sysfs_emit()
or sysfs_emit_at() when formatting the value to be returned to user space.

coccinelle complains that there are still a couple of functions that use
snprintf(). Convert them to sysfs_emit().

sprintf() and scnprintf() will be converted as well if they have.

Generally, this patch is generated by
make coccicheck M=<path/to/file> MODE=patch \
COCCI=scripts/coccinelle/api/device_attr_show.cocci

No functional change intended

CC: Helge Deller <deller@gmx.de>
CC: linux-omap@vger.kernel.org
CC: linux-fbdev@vger.kernel.org
CC: dri-devel@lists.freedesktop.org
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
---
V3:
   split it from a mess of drm,fbdev, becuase they are not the same subsystem.

V2:
   Fix missing '+' before '=' in drivers/video/fbdev/omap2/omapfb/displays/panel-tpo-td043mtea1.c

This is a part of the work "Fix coccicheck device_attr_show warnings"[1]
Split them per subsystem so that the maintainer can review it easily
[1] https://lore.kernel.org/lkml/20240116041129.3937800-1-lizhijian@fujitsu.com/
---
 .../omap2/omapfb/displays/panel-tpo-td043mtea1.c     | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/drivers/video/fbdev/omap2/omapfb/displays/panel-tpo-td043mtea1.c b/drivers/video/fbdev/omap2/omapfb/displays/panel-tpo-td043mtea1.c
index 477789cff8e0..3624452e1dd0 100644
--- a/drivers/video/fbdev/omap2/omapfb/displays/panel-tpo-td043mtea1.c
+++ b/drivers/video/fbdev/omap2/omapfb/displays/panel-tpo-td043mtea1.c
@@ -228,14 +228,10 @@ static ssize_t tpo_td043_gamma_show(struct device *dev,
 	int ret;
 	int i;
 
-	for (i = 0; i < ARRAY_SIZE(ddata->gamma); i++) {
-		ret = snprintf(buf + len, PAGE_SIZE - len, "%u ",
-				ddata->gamma[i]);
-		if (ret < 0)
-			return ret;
-		len += ret;
-	}
-	buf[len - 1] = '\n';
+	for (i = 0; i < ARRAY_SIZE(ddata->gamma); i++)
+		len += sysfs_emit_at(buf, len, "%u ", ddata->gamma[i]);
+	if (len)
+		buf[len - 1] = '\n';
 
 	return len;
 }
-- 
2.29.2

Re: [PATCH v3] video: fbdev: panel-tpo-td043mtea1: Convert sprintf() family to sysfs_emit() family

[Helge Deller]

On 3/19/24 10:23, Li Zhijian wrote:
> Per filesystems/sysfs.rst, show() should only use sysfs_emit()
> or sysfs_emit_at() when formatting the value to be returned to user space.
>
> coccinelle complains that there are still a couple of functions that use
> snprintf(). Convert them to sysfs_emit().
>
> sprintf() and scnprintf() will be converted as well if they have.
>
> Generally, this patch is generated by
> make coccicheck M=<path/to/file> MODE=patch \
> COCCI=scripts/coccinelle/api/device_attr_show.cocci
>
> No functional change intended
>
> CC: Helge Deller <deller@gmx.de>
> CC: linux-omap@vger.kernel.org
> CC: linux-fbdev@vger.kernel.org
> CC: dri-devel@lists.freedesktop.org
> Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>

applied to fbdev git tree.
Thanks!
Helge

> ---
> V3:
>     split it from a mess of drm,fbdev, becuase they are not the same subsystem.
>
> V2:
>     Fix missing '+' before '=' in drivers/video/fbdev/omap2/omapfb/displays/panel-tpo-td043mtea1.c
>
> This is a part of the work "Fix coccicheck device_attr_show warnings"[1]
> Split them per subsystem so that the maintainer can review it easily
> [1] https://lore.kernel.org/lkml/20240116041129.3937800-1-lizhijian@fujitsu.com/
> ---
>   .../omap2/omapfb/displays/panel-tpo-td043mtea1.c     | 12 ++++--------
>   1 file changed, 4 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/video/fbdev/omap2/omapfb/displays/panel-tpo-td043mtea1.c b/drivers/video/fbdev/omap2/omapfb/displays/panel-tpo-td043mtea1.c
> index 477789cff8e0..3624452e1dd0 100644
> --- a/drivers/video/fbdev/omap2/omapfb/displays/panel-tpo-td043mtea1.c
> +++ b/drivers/video/fbdev/omap2/omapfb/displays/panel-tpo-td043mtea1.c
> @@ -228,14 +228,10 @@ static ssize_t tpo_td043_gamma_show(struct device *dev,
>   	int ret;
>   	int i;
>
> -	for (i = 0; i < ARRAY_SIZE(ddata->gamma); i++) {
> -		ret = snprintf(buf + len, PAGE_SIZE - len, "%u ",
> -				ddata->gamma[i]);
> -		if (ret < 0)
> -			return ret;
> -		len += ret;
> -	}
> -	buf[len - 1] = '\n';
> +	for (i = 0; i < ARRAY_SIZE(ddata->gamma); i++)
> +		len += sysfs_emit_at(buf, len, "%u ", ddata->gamma[i]);
> +	if (len)
> +		buf[len - 1] = '\n';
>
>   	return len;
>   }