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Diffstat (limited to 'doc/develop/logging.rst')
| -rw-r--r-- | doc/develop/logging.rst | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/doc/develop/logging.rst b/doc/develop/logging.rst index 622ad6ad1af..f4e925048e8 100644 --- a/doc/develop/logging.rst +++ b/doc/develop/logging.rst @@ -117,11 +117,24 @@ can be used whenever your function returns an error value: .. code-block:: c - return log_ret(uclass_first_device(UCLASS_MMC, &dev)); + return log_ret(uclass_first_device_err(UCLASS_MMC, &dev)); This will write a log record when an error code is detected (a value < 0). This can make it easier to trace errors that are generated deep in the call stack. +The log_msg_ret() variant will print a short string if CONFIG_LOG_ERROR_RETURN +is enabled. So long as the string is unique within the function you can normally +determine exactly which call failed: + +.. code-block:: c + + ret = gpio_request_by_name(dev, "cd-gpios", 0, &desc, GPIOD_IS_IN); + if (ret) + return log_msg_ret("gpio", ret); + +Some functions return 0 for success and any other value is an error. For these, +log_retz() and log_msg_retz() are available. + Convenience functions ~~~~~~~~~~~~~~~~~~~~~ |