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 omitted or implemented only partially. dev_err_probe helps to replace such code sequences with simple call, so code: if (err != -EPROBE_DEFER) dev_err(dev, ...); return err; becomes: return dev_err_probe(dev, err, ...);
Signed-off-by: Andrzej Hajda a.hajda@samsung.com Reviewed-by: Rafael J. Wysocki rafael@kernel.org --- drivers/base/core.c | 42 ++++++++++++++++++++++++++++++++++++++++++ include/linux/device.h | 3 +++ 2 files changed, 45 insertions(+)
diff --git a/drivers/base/core.c b/drivers/base/core.c index 67d39a90b45c..3a827c82933f 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -3953,6 +3953,48 @@ define_dev_printk_level(_dev_info, KERN_INFO);
#endif
+/** + * dev_err_probe - 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 debug or error message depending if the error value is + * -EPROBE_DEFER and propagate error upwards. + * It replaces code sequence: + * if (err != -EPROBE_DEFER) + * dev_err(dev, ...); + * else + * dev_dbg(dev, ...); + * return err; + * with + * return dev_err_probe(dev, err, ...); + * + * Returns @err. + * + */ +int dev_err_probe(const struct device *dev, int err, const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + + va_start(args, fmt); + vaf.fmt = fmt; + vaf.va = &args; + + if (err != -EPROBE_DEFER) + dev_err(dev, "error %d: %pV", err, &vaf); + else + dev_dbg(dev, "error %d: %pV", err, &vaf); + + va_end(args); + + return err; +} +EXPORT_SYMBOL_GPL(dev_err_probe); + 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 15460a5ac024..6b2272ae9af8 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -964,6 +964,9 @@ void device_link_remove(void *consumer, struct device *supplier); void device_links_supplier_sync_state_pause(void); void device_links_supplier_sync_state_resume(void);
+extern __printf(3, 4) +int dev_err_probe(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))