From: Huazhong Tan <tanhuazhong@huawei.com>
Date: Mon, 2 Jul 2018 15:50:21 +0800
Subject: net: hns3: simplify hclge_cmd_csq_clean
Patch-mainline: v4.19-rc1
Git-commit: 1c1270da47a290cd3c880b933bb06073c0365e2c
References: bsc#1104353 FATE#326415

csq is used as a ring buffer, the value of the desc will be replaced
in next use. This patch removes the unnecessary memset, and just
updates the next_to_clean.

Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_cmd.c |   21 ++++-------------
 1 file changed, 5 insertions(+), 16 deletions(-)

--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_cmd.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_cmd.c
@@ -152,31 +152,20 @@ static int hclge_cmd_csq_clean(struct hc
 {
 	struct hclge_dev *hdev = container_of(hw, struct hclge_dev, hw);
 	struct hclge_cmq_ring *csq = &hw->cmq.csq;
-	u16 ntc = csq->next_to_clean;
-	struct hclge_desc *desc;
-	int clean = 0;
 	u32 head;
+	int clean;
 
-	desc = &csq->desc[ntc];
 	head = hclge_read_dev(hw, HCLGE_NIC_CSQ_HEAD_REG);
 	rmb(); /* Make sure head is ready before touch any data */
 
 	if (!is_valid_csq_clean_head(csq, head)) {
-		dev_warn(&hdev->pdev->dev, "wrong head (%d, %d-%d)\n", head,
-			   csq->next_to_use, csq->next_to_clean);
+		dev_warn(&hdev->pdev->dev, "wrong cmd head (%d, %d-%d)\n", head,
+			 csq->next_to_use, csq->next_to_clean);
 		return 0;
 	}
 
-	while (head != ntc) {
-		memset(desc, 0, sizeof(*desc));
-		ntc++;
-		if (ntc == csq->desc_num)
-			ntc = 0;
-		desc = &csq->desc[ntc];
-		clean++;
-	}
-	csq->next_to_clean = ntc;
-
+	clean = (head - csq->next_to_clean + csq->desc_num) % csq->desc_num;
+	csq->next_to_clean = head;
 	return clean;
 }