[PATCH v2] i40e: fix issue of reconfigure hash enable flags

[Helin Zhang <helin.zhang@intel.com>]

It fixes the issue of not re-configuring hash enable flags (HENA)
if there is no key.

Fixes: d0a349409bd7 ("i40e: support AQ based RSS config")

Signed-off-by: Helin Zhang <helin.zhang@intel.com>
---
 drivers/net/i40e/i40e_ethdev.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

v2 changes:
Removed useless checks.

diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
index 2c51a0b..4bc258a 100644
--- a/drivers/net/i40e/i40e_ethdev.c
+++ b/drivers/net/i40e/i40e_ethdev.c
@@ -5663,9 +5663,14 @@ i40e_set_rss_key(struct i40e_vsi *vsi, uint8_t *key, uint8_t key_len)
 	struct i40e_hw *hw = I40E_VSI_TO_HW(vsi);
 	int ret = 0;
 
-	if (!key || key_len != ((I40E_PFQF_HKEY_MAX_INDEX + 1) *
-		sizeof(uint32_t)))
+	if (!key || key_len == 0) {
+		PMD_DRV_LOG(DEBUG, "No key to be configured");
+		return 0;
+	} else if (key_len != (I40E_PFQF_HKEY_MAX_INDEX + 1) *
+		sizeof(uint32_t)) {
+		PMD_DRV_LOG(ERR, "Invalid key length %u", key_len);
 		return -EINVAL;
+	}
 
 	if (pf->flags & I40E_FLAG_RSS_AQ_CAPABLE) {
 		struct i40e_aqc_get_set_rss_key_data *key_dw =
-- 
1.9.3