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;
+

+               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