[PATCH net-next] ethtool: Clarify len/n_stats fields in/out semantics

[Gal Pressman <gal@nvidia.com>]

Document that the 'len' field in ethtool_gstrings and 'n_stats' field in
ethtool_stats serve dual purposes: on entry they specify the number of
items requested, and on return they indicate the number actually
returned (which is not necessarily the same).

Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Signed-off-by: Gal Pressman <gal@nvidia.com>
---
 include/uapi/linux/ethtool.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index eb7ff2602fbb..f66adf15a3c8 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -1094,7 +1094,8 @@ enum ethtool_module_fw_flash_status {
  * struct ethtool_gstrings - string set for data tagging
  * @cmd: Command number = %ETHTOOL_GSTRINGS
  * @string_set: String set ID; one of &enum ethtool_stringset
- * @len: On return, the number of strings in the string set
+ * @len: On entry, the number of strings requested.
+ *	On return, the number of strings returned.
  * @data: Buffer for strings.  Each string is null-padded to a size of
  *	%ETH_GSTRING_LEN.
  *
@@ -1177,7 +1178,8 @@ struct ethtool_test {
 /**
  * struct ethtool_stats - device-specific statistics
  * @cmd: Command number = %ETHTOOL_GSTATS
- * @n_stats: On return, the number of statistics
+ * @n_stats: On entry, the number of stats requested.
+	On return, the number of stats returned.
  * @data: Array of statistics
  *
  * Users must use %ETHTOOL_GSSET_INFO or %ETHTOOL_GDRVINFO to find the
-- 
2.40.1