| Message ID | 20200629112242.18380-2-a.hajda@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v7,1/4] driver core: add device probe log helper | expand |
On Mon, Jun 29, 2020 at 2:22 PM Andrzej Hajda <a.hajda@samsung.com> wrote: > > 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, ...); FWIW, Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> (I'm fine with current code, though, consider below comments) > 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) Perhaps positive conditional. > + dev_err(dev, "error %d: %pV", err, &vaf); > + else > + dev_dbg(dev, "error %d: %pV", err, &vaf); Perhaps {} to be added here. > + > + 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)) > -- > 2.17.1 >
On Mon, Jun 29, 2020 at 01:22:39PM +0200, Andrzej Hajda wrote: > 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. Reviewed-by: Mark Brown <broonie@kernel.org>
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))