On 19/03/2024 16:07, Neil Armstrong wrote:

Hi,

On 19/03/2024 04:55, Li Zhijian wrote:

quoted

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

Please split patches in 2, while the driver targets the same hw, they
are not under the same subsystems.

Got it, i will do that soon.

Thanks
Zhijian

Neil

quoted

CC: Neil Armstrong <neil.armstrong@linaro.org>
CC: Jessica Zhang <redacted>
CC: Sam Ravnborg <redacted>
CC: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
CC: Maxime Ripard <mripard@kernel.org>
CC: Thomas Zimmermann <tzimmermann@suse.de>
CC: David Airlie <airlied@gmail.com>
CC: Daniel Vetter <redacted>
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 <redacted>
---
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/ (local)
---
  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..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;
  }