Re: [PATCH] Remove error prints for devm_add_action_or_reset()
From: Uwe Kleine-König <ukleinek@kernel.org>
Date: 2025-07-01 17:44:20
Also in:
imx, linux-amlogic, linux-arm-msm, linux-gpio, linux-i2c, linux-iio, linux-input, linux-mediatek, linux-mmc, linux-omap, linux-phy, linux-pm, linux-pwm, linux-rockchip, linux-samsung-soc, linux-scsi, linux-sound, linux-spi, linux-usb, lkml
Subsystem:
driver core, kobjects, debugfs and sysfs, the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Linus Torvalds
Hello, On Tue, Jul 01, 2025 at 05:03:33PM +0200, Waqar Hameed wrote:
drivers/pwm/pwm-meson.c | 3 +--
Looking at this driver I tried the following:
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 3809baed42f3..58a2ab74f14c 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c@@ -5062,7 +5062,7 @@ static void __dev_probe_failed(const struct device *dev, int err, bool fatal, * * Returns @err. */ -int dev_err_probe(const struct device *dev, int err, const char *fmt, ...) +int _dev_err_probe(const struct device *dev, int err, const char *fmt, ...) { va_list vargs;
@@ -5075,7 +5075,7 @@ int dev_err_probe(const struct device *dev, int err, const char *fmt, ...) return err; } -EXPORT_SYMBOL_GPL(dev_err_probe); +EXPORT_SYMBOL_GPL(_dev_err_probe); /** * dev_warn_probe - probe error check and log helper
diff --git a/include/linux/dev_printk.h b/include/linux/dev_printk.h
index eb2094e43050..23ef250727f1 100644
--- a/include/linux/dev_printk.h
+++ b/include/linux/dev_printk.h@@ -275,7 +275,13 @@ do { \ WARN_ONCE(condition, "%s %s: " format, \ dev_driver_string(dev), dev_name(dev), ## arg) -__printf(3, 4) int dev_err_probe(const struct device *dev, int err, const char *fmt, ...); +__printf(3, 4) int _dev_err_probe(const struct device *dev, int err, const char *fmt, ...); + +#define dev_err_probe(dev, err, ...) ( \ + (__builtin_constant_p(err) && err == -ENOMEM) ? err : _dev_err_probe(dev, err, __VA_ARGS__) \ +) + + __printf(3, 4) int dev_warn_probe(const struct device *dev, int err, const char *fmt, ...); /* Simple helper for dev_err_probe() when ERR_PTR() is to be returned. */
diff --git a/include/linux/device/devres.h b/include/linux/device/devres.h
index ae696d10faff..abfa5152b5a7 100644
--- a/include/linux/device/devres.h
+++ b/include/linux/device/devres.h@@ -157,8 +157,11 @@ static inline int __devm_add_action_or_reset(struct device *dev, void (*action)( int ret; ret = __devm_add_action(dev, action, data, name); - if (ret) + if (ret) { + if (ret != -ENOMEM) + __builtin_unreachable(); action(data); + } return ret; }
With that
ret = devm_add_action_or_reset(dev, meson_pwm_s4_put_clk,
meson->channels[i].clk);
if (ret)
return dev_err_probe(dev, ret,
"Failed to add clk_put action\n");
from drivers/pwm/pwm-meson.c is optimized to
ret = devm_add_action_or_reset(dev, meson_pwm_s4_put_clk,
meson->channels[i].clk);
if (ret)
return ret;
.
I would prefer this approach, because a) there is no need to drop all
dev_err_probe()s after devm_add_action_or_reset() and b) the
dev_err_probe()s could stay for consistency in the error paths of a
driver.
Best regards
Uwe Attachments
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