2024-03-19 03:43:42

by Li Zhijian

Subject: [PATCH] drm,fbdev: td043mtea1: Convert sprintf() family to sysfs_emit() family

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: Neil Armstrong <[email protected]>
CC: Jessica Zhang <[email protected]>
CC: Sam Ravnborg <[email protected]>
CC: Maarten Lankhorst <[email protected]>
CC: Maxime Ripard <[email protected]>
CC: Thomas Zimmermann <[email protected]>
CC: David Airlie <[email protected]>
CC: Daniel Vetter <[email protected]>
CC: Helge Deller <[email protected]>
CC: [email protected]
CC: [email protected]
CC: [email protected]
Signed-off-by: Li Zhijian <[email protected]>
---
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/[email protected]/
---
drivers/gpu/drm/panel/panel-tpo-td043mtea1.c | 13 ++++---------
.../omap2/omapfb/displays/panel-tpo-td043mtea1.c | 12 ++++--------
2 files changed, 8 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-tpo-td043mtea1.c b/drivers/gpu/drm/panel/panel-tpo-td043mtea1.c
index cf4609bb9b1d..0983fe47eb5a 100644
--- a/drivers/gpu/drm/panel/panel-tpo-td043mtea1.c
+++ b/drivers/gpu/drm/panel/panel-tpo-td043mtea1.c
@@ -242,16 +242,11 @@ static ssize_t gamma_show(struct device *dev, struct device_attribute *attr,
struct td043mtea1_panel *lcd = dev_get_drvdata(dev);
ssize_t len = 0;
unsigned int i;
- int ret;

- for (i = 0; i < ARRAY_SIZE(lcd->gamma); i++) {
- ret = snprintf(buf + len, PAGE_SIZE - len, "%u ",
- lcd->gamma[i]);
- if (ret < 0)
- return ret;
- len += ret;
- }
- buf[len - 1] = '\n';
+ for (i = 0; i < ARRAY_SIZE(lcd->gamma); i++)
+ len += sysfs_emit_at(buf, len, "%u ", lcd->gamma[i]);
+ if (len)
+ buf[len - 1] = '\n';

return len;
}
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..040a17a05baa 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

2024-03-19 04:02:01

by Li Zhijian

Subject: Re: [PATCH] drm,fbdev: td043mtea1: Convert sprintf() family to sysfs_emit() family

On 19/03/2024 11:43, Li Zhijian wrote:
> 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..040a17a05baa 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]);

It should be
len += sysfs_emit_at(buf, len, "%u ", ddata->gamma[i]);

just posted V2 to fix this.


Thanks
Zhijian

> + if (len)
> + buf[len - 1] = '\n';
>