[PATCH 1/3] driver core: add probe_err log helper
From: Andrzej Hajda <hidden>
Date: 2018-10-16 07:22:56
Also in:
lkml
Subsystem:
driver core, kobjects, debugfs and sysfs, the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Linus Torvalds
Possibly related (same subject, not in this thread)
- 2018-10-18 · Re: [PATCH 1/3] driver core: add probe_err log helper · Joe Perches <joe@perches.com>
- 2018-10-17 · Re: [PATCH 1/3] driver core: add probe_err log helper · Andy Shevchenko <hidden>
- 2018-10-17 · Re: [PATCH 1/3] driver core: add probe_err log helper · Russell King - ARM Linux <linux@armlinux.org.uk>
- 2018-10-16 · Re: [PATCH 1/3] driver core: add probe_err log helper · Andy Shevchenko <hidden>
- 2018-10-16 · Re: [PATCH 1/3] driver core: add probe_err log helper · Andrzej Hajda <hidden>
During probe every time driver gets resource it should usually check for error printk some message if it is not -EPROBE_DEFER and return the error. This pattern is simple but requires adding few lines after any resource acquisition code, as a result it is often omited or implemented only partially. probe_err helps to replace such code seqences with simple call, so code: if (err != -EPROBE_DEFER) dev_err(dev, ...); return err; becomes: return probe_err(dev, err, ...); Signed-off-by: Andrzej Hajda <redacted> --- drivers/base/core.c | 37 +++++++++++++++++++++++++++++++++++++ include/linux/device.h | 2 ++ 2 files changed, 39 insertions(+)
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 04bbcd779e11..23fabefb217a 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c@@ -3067,6 +3067,43 @@ define_dev_printk_level(_dev_info, KERN_INFO); #endif +/** + * probe_err - probe error check and log helper + * @dev: the pointer to the struct device + * @err: error value to test + * @fmt: printf-style format string + * @...: arguments as specified in the format string + * + * This helper implements common pattern present in probe functions for error + * checking: print message if the error is not -EPROBE_DEFER and propagate it. + * It replaces code sequence: + * if (err != -EPROBE_DEFER) + * dev_err(dev, ...); + * return err; + * with + * return probe_err(dev, err, ...); + * + * Returns @err. + * + */ +int probe_err(const struct device *dev, int err, const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + + if (err != -EPROBE_DEFER) { + va_start(args, fmt); + + vaf.fmt = fmt; + vaf.va = &args; + + __dev_printk(KERN_ERR, dev, &vaf); + va_end(args); + } + + return err; +} + static inline bool fwnode_is_primary(struct fwnode_handle *fwnode) { return fwnode && !IS_ERR(fwnode->secondary);
diff --git a/include/linux/device.h b/include/linux/device.h
index 90224e75ade4..06c2c797d132 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h@@ -1577,6 +1577,8 @@ do { \ WARN_ONCE(condition, "%s %s: " format, \ dev_driver_string(dev), dev_name(dev), ## arg) +int probe_err(const struct device *dev, int err, const char *fmt, ...); + /* Create alias, so I can be autoloaded. */ #define MODULE_ALIAS_CHARDEV(major,minor) \ MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
--
2.18.0