From: Ivan Ilchenko <ivan.ilche...@oktetlabs.ru>
Document valid combinations of input arguments in accordance with
current implementation in ethdev.
Fixes: 79c913a42f0 ("ethdev: retrieve xstats by ID")
Cc: sta...@dpdk.org
Signed-off-by: Ivan Ilchenko <ivan.ilche...@oktetlabs.ru>
Signed-off-by: Andrew Rybchenko <andrew.rybche...@oktetlabs.ru>
Reviewed-by: Andy Moreton <amore...@xilinx.com>
---
lib/ethdev/rte_ethdev.h | 35 +++++++++++++++++++----------------
1 file changed, 19 insertions(+), 16 deletions(-)
diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
index 224c6c980a..f597171c97 100644
--- a/lib/ethdev/rte_ethdev.h
+++ b/lib/ethdev/rte_ethdev.h
@@ -2899,21 +2899,23 @@ int rte_eth_xstats_get(uint16_t port_id, struct
rte_eth_xstat *xstats,
* @param port_id
* The port identifier of the Ethernet device.
* @param xstats_names
- * An rte_eth_xstat_name array of at least *size* elements to
- * be filled. If set to NULL, the function returns the required number
- * of elements.
- * @param ids
- * IDs array given by app to retrieve specific statistics
+ * Array to be filled in with names of requested device statistics.
+ * Must not be NULL if @p ids are specified (not NULL).
* @param size
- * The size of the xstats_names array (number of elements).
+ * Number of elements in @p xstats_names array (if not NULL) and in
+ * @p ids array (if not NULL). Must be 0 if both array pointers are NULL.
+ * @param ids
+ * IDs array given by app to retrieve specific statistics. May be NULL to
+ * retrieve names of all available statistics or, if @p xstats_names is
+ * NULL as well, just the number of available statistics.
* @return
* - A positive value lower or equal to size: success. The return value
* is the number of entries filled in the stats table.
- * - A positive value higher than size: error, the given statistics table
+ * - A positive value higher than size: success. The given statistics table
* is too small. The return value corresponds to the size that should
* be given to succeed. The entries in the table are not valid and
* shall not be used by the caller.
- * - A negative value on error (invalid port id).
+ * - A negative value on error.
*/
int
rte_eth_xstats_get_names_by_id(uint16_t port_id,
@@ -2926,22 +2928,23 @@ rte_eth_xstats_get_names_by_id(uint16_t port_id,
* @param port_id
* The port identifier of the Ethernet device.
* @param ids
- * A pointer to an ids array passed by application. This tells which
- * statistics values function should retrieve. This parameter
- * can be set to NULL if size is 0. In this case function will retrieve
- * all available statistics.
+ * IDs array given by app to retrieve specific statistics. May be NULL to
+ * retrieve all available statistics or, if @p values is NULL as well,
+ * just the number of available statistics.
* @param values
- * A pointer to a table to be filled with device statistics values.
+ * Array to be filled in with requested device statistics.
+ * Must not be NULL if ids are specified (not NULL).
* @param size
- * The size of the ids array (number of elements).
+ * Number of elements in @p values array (if not NULL) and in @p ids
+ * array (if not NULL). Must be 0 if both array pointers are NULL.
* @return
* - A positive value lower or equal to size: success. The return value
* is the number of entries filled in the stats table.
- * - A positive value higher than size: error, the given statistics table
+ * - A positive value higher than size: success: The given statistics table
* is too small. The return value corresponds to the size that should
* be given to succeed. The entries in the table are not valid and
* shall not be used by the caller.
- * - A negative value on error (invalid port id).
+ * - A negative value on error.
*/
int rte_eth_xstats_get_by_id(uint16_t port_id, const uint64_t *ids,
uint64_t *values, unsigned int size);
--
2.30.2
