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 <neil.armstr...@linaro.org> CC: Jessica Zhang <quic_jessz...@quicinc.com> CC: Sam Ravnborg <s...@ravnborg.org> CC: Maarten Lankhorst <maarten.lankho...@linux.intel.com> CC: Maxime Ripard <mrip...@kernel.org> CC: Thomas Zimmermann <tzimmerm...@suse.de> CC: David Airlie <airl...@gmail.com> CC: Daniel Vetter <dan...@ffwll.ch> CC: Helge Deller <del...@gmx.de> CC: linux-o...@vger.kernel.org CC: linux-fb...@vger.kernel.org CC: dri-devel@lists.freedesktop.org Signed-off-by: Li Zhijian <lizhij...@fujitsu.com> --- 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-lizhij...@fujitsu.com/ --- 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
