1 files changed, 14 insertions, 11 deletions

diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index d47d31d6fa0e..e3c7a719c76b 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -850,21 +850,23 @@ struct ethtool_rxfh_indir {
  * struct ethtool_rxfh - command to get/set RX flow hash indir or/and hash key.
  * @cmd: Specific command number - %ETHTOOL_GRSSH or %ETHTOOL_SRSSH
  * @rss_context: RSS context identifier.
- * @indir_size: On entry, the array size of the user buffer, which may be zero.
- *              On return from %ETHTOOL_GRSSH, the array size of the hardware
- *              indirection table.
- * @key_size:   On entry, the array size of the user buffer in bytes,
- *              which may be zero.
- *              On return from %ETHTOOL_GRSSH, the size of the RSS hash key.
+ * @indir_size: On entry, the array size of the user buffer for the
+ *      indirection table, which may be zero, or (for %ETHTOOL_SRSSH),
+ *      %ETH_RXFH_INDIR_NO_CHANGE.  On return from %ETHTOOL_GRSSH,
+ *      the array size of the hardware indirection table.
+ * @key_size: On entry, the array size of the user buffer for the hash key,
+ *      which may be zero.  On return from %ETHTOOL_GRSSH, the size of the
+ *      hardware hash key.
  * @rsvd:       Reserved for future extensions.
  * @rss_config: RX ring/queue index for each hash value i.e., indirection table
- *              of size @indir_size followed by hash key of size @key_size.
+ *      of @indir_size __u32 elements, followed by hash key of @key_size
+ *      bytes.
  *
  * For %ETHTOOL_GRSSH, a @indir_size and key_size of zero means that only the
- * size should be returned.  For %ETHTOOL_SRSSH, a @indir_size of 0xDEADBEEF
- * means that indir table setting is not requested and a @indir_size of zero
- * means the indir table should be reset to default values.  This last feature
- * is not supported by the original implementations.
+ * size should be returned.  For %ETHTOOL_SRSSH, an @indir_size of
+ * %ETH_RXFH_INDIR_NO_CHANGE means that indir table setting is not requested
+ * and a @indir_size of zero means the indir table should be reset to default
+ * values.
  */
 struct ethtool_rxfh {
         __u32   cmd;
@@ -874,6 +876,7 @@ struct ethtool_rxfh {
         __u32   rsvd[2];
         __u32   rss_config[0];
 };
+#define ETH_RXFH_INDIR_NO_CHANGE        0xffffffff
 
 /**
  * struct ethtool_rx_ntuple_flow_spec - specification for RX flow filter