driver core: add device probe log helper

[ Upstream commit a787e5400a1ceeb0ef92d71ec43aeb35b1fa1334 ]

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>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20200713144324.23654-2-a.hajda@samsung.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: ef45e8400f5b ("net: ll_temac: fix error checking of irq_of_parse_and_map()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Andrzej Hajda 2020-07-13 16:43:21 +02:00 committed by Greg Kroah-Hartman
parent 227b8ce59c
commit 97d8a0bbda
2 changed files with 45 additions and 0 deletions

View File

@ -3399,6 +3399,48 @@ 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);

View File

@ -1871,6 +1871,9 @@ do { \
WARN_ONCE(condition, "%s %s: " format, \
dev_driver_string(dev), dev_name(dev), ## arg)
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))