From: Arthur Kiyanovski <akiyano@amazon.com>
Date: Sun, 3 May 2020 09:52:10 +0000
Subject: net: ena: avoid unnecessary admin command when RSS function set fails
Patch-mainline: v5.8-rc1
Git-commit: 80f8443fcdaa27871a233d08e9142612e6ade77c
References: bsc#1174852

Currently when ena_set_hash_function() fails the hash function is
restored to the previous value by calling an admin command to get
the hash function from the device.

In this commit we avoid the admin command, by saving the previous
hash function before calling ena_set_hash_function() and using this
previous value to restore the hash function in case of failure of
ena_set_hash_function().

Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/amazon/ena/ena_com.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/amazon/ena/ena_com.c
+++ b/drivers/net/ethernet/amazon/ena/ena_com.c
@@ -2287,6 +2287,7 @@ int ena_com_fill_hash_function(struct en
 	struct ena_admin_get_feat_resp get_resp;
 	struct ena_admin_feature_rss_flow_hash_control *hash_key =
 		rss->hash_key;
+	enum ena_admin_hash_functions old_func;
 	int rc;
 
 	/* Make sure size is a mult of DWs */
@@ -2326,12 +2327,13 @@ int ena_com_fill_hash_function(struct en
 		return -EINVAL;
 	}
 
+	old_func = rss->hash_func;
 	rss->hash_func = func;
 	rc = ena_com_set_hash_function(ena_dev);
 
 	/* Restore the old function */
 	if (unlikely(rc))
-		ena_com_get_hash_function(ena_dev, NULL, NULL);
+		rss->hash_func = old_func;
 
 	return rc;
 }