1 files changed, 27 insertions, 10 deletions
diff --git a/include/odp/api/errno.h b/include/odp/api/errno.h
index 982980738..33998b61b 100644
--- a/include/odp/api/errno.h
+++ b/include/odp/api/errno.h
@@ -17,20 +17,38 @@
 extern "C" {
 #endif
 
-/** @defgroup odp_errno ODP ERRNO
+/**
+ * @defgroup odp_errno ODP ERRNO
+ * @details
+ * <b> ODP errno </b>
+ *
+ * ODP errno (error number) is a thread local variable that any ODP function may
+ * set on a failure. It expresses additional information about the cause of
+ * the latest failure. A successful function call never sets errno. Application
+ * may initialize errno to zero at anytime by calling odp_errno_zero(). Other
+ * ODP functions never set errno to zero. Valid errno values are non-zero
+ * and implementation specific. It's also implementation specific which
+ * functions set errno in addition to those explicitly specified by
+ * the API spec. ODP errno is initially zero.
+ *
  *  @{
  */
 
 /**
-* Return latest ODP errno
+* Latest ODP errno
 *
-* @return ODP errno
-* @retval 0 No error
+* Returns the current ODP errno value on the calling thread. A non-zero value
+* indicates cause of the latest errno setting failure.
+*
+* @return Latest ODP errno value
+* @retval 0    Errno has not been set since the last initialization to zero
 */
 int odp_errno(void);
 
 /**
 * Set ODP errno to zero
+*
+* Sets errno value to zero on the calling thread.
 */
 void odp_errno_zero(void);
 
@@ -40,20 +58,19 @@ void odp_errno_zero(void);
 * Interprets the value of ODP errno as an error message, and prints it,
 * optionally preceding it with the custom message specified in str.
 *
-* @param str NULL, or pointer to the string to be appended
+* @param str   Pointer to the string to be appended, or NULL
 */
 void odp_errno_print(const char *str);
 
 /**
 * Error message string
 *
-* Interprets the value of ODP errno, generating a string with a
-* message that describes the error.
-* It uses the system definition of errno.
+* Interprets the value of ODP errno, generating a string with a message that
+* describes the error. Errno values and messages are implementation specific.
 *
-* @param errnum	Error code
+* @param errnum	 ODP errno value
 *
-* @retval Pointer to the string
+* @retval Pointer to the error message string
 */
 const char *odp_errno_str(int errnum);