From: Huazhong Tan <tanhuazhong@huawei.com>
Date: Mon, 16 Jul 2018 16:36:21 +0100
Subject: net: hns3: Prevent to request reset frequently
Patch-mainline: v4.19-rc1
Git-commit: 9de0b86f64444e5bddc0c4687e23c36ab52d1fcf
References: bsc#1104353 FATE#326415

Netdevice reset should not be requested frequently, a new one
must wait a moment since there may be some work not completed.

Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@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_main.c |   13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
@@ -2819,7 +2819,10 @@ static void hclge_clear_reset_cause(stru
 
 static void hclge_reset(struct hclge_dev *hdev)
 {
+	struct hnae3_handle *handle;
+
 	/* perform reset of the stack & ae device for a client */
+	handle = &hdev->vport[0].nic;
 	rtnl_lock();
 	hclge_notify_client(hdev, HNAE3_DOWN_CLIENT);
 
@@ -2836,6 +2839,7 @@ static void hclge_reset(struct hclge_dev
 	}
 
 	hclge_notify_client(hdev, HNAE3_UP_CLIENT);
+	handle->last_reset_time = jiffies;
 	rtnl_unlock();
 }
 
@@ -2849,8 +2853,13 @@ static void hclge_reset_event(struct hna
 	 * know this if last reset request did not occur very recently (watchdog
 	 * timer = 5*HZ, let us check after sufficiently large time, say 4*5*Hz)
 	 * In case of new request we reset the "reset level" to PF reset.
+	 * And if it is a repeat reset request of the most recent one then we
+	 * want to make sure we throttle the reset request. Therefore, we will
+	 * not allow it again before 3*HZ times.
 	 */
-	if (time_after(jiffies, (handle->last_reset_time + 4 * 5 * HZ)))
+	if (time_before(jiffies, (handle->last_reset_time + 3 * HZ)))
+		return;
+	else if (time_after(jiffies, (handle->last_reset_time + 4 * 5 * HZ)))
 		handle->reset_level = HNAE3_FUNC_RESET;
 
 	dev_info(&hdev->pdev->dev, "received reset event , reset type is %d",
@@ -2862,8 +2871,6 @@ static void hclge_reset_event(struct hna
 
 	if (handle->reset_level < HNAE3_GLOBAL_RESET)
 		handle->reset_level++;
-
-	handle->last_reset_time = jiffies;
 }
 
 static void hclge_reset_subtask(struct hclge_dev *hdev)