From: Yunsheng Lin <linyunsheng@huawei.com>
Date: Fri, 1 Jun 2018 17:52:06 +0100
Subject: net: hns3: Fix for hclge_reset running repeatly problem
Patch-mainline: v4.18-rc1
Git-commit: cd8c5c269b1d807028e939293002c989e7c07e51
References: bsc#1104353 FATE#326415

When hardware sends the HCLGE_VECTOR0_EVENT_RST event through
hclge_misc_irq_handle, currently driver enables misc_vector in
the interrupt handle, and hardware generates the same interrupt
for the same reset event again and again until the reset is
complete, which causes hclge_reset running repeatly problem.

This patch fixes by enabling the misc_vector after reset is
complete.

Fixes: 4ed340ab8f49 ("net: hns3: Add reset process in hclge_main")
Signed-off-by: Yunsheng Lin <linyunsheng@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 |   40 +++++++++++++---
 1 file changed, 34 insertions(+), 6 deletions(-)

--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
@@ -2587,9 +2587,11 @@ static irqreturn_t hclge_misc_irq_handle
 		break;
 	}
 
-	/* we should clear the source of interrupt */
-	hclge_clear_event_cause(hdev, event_cause, clearval);
-	hclge_enable_vector(&hdev->misc_vector, true);
+	/* clear the source of interrupt if it is not cause by reset */
+	if (event_cause != HCLGE_VECTOR0_EVENT_RST) {
+		hclge_clear_event_cause(hdev, event_cause, clearval);
+		hclge_enable_vector(&hdev->misc_vector, true);
+	}
 
 	return IRQ_HANDLED;
 }
@@ -2777,6 +2779,33 @@ static enum hnae3_reset_type hclge_get_r
 	return rst_level;
 }
 
+static void hclge_clear_reset_cause(struct hclge_dev *hdev)
+{
+	u32 clearval = 0;
+
+	switch (hdev->reset_type) {
+	case HNAE3_IMP_RESET:
+		clearval = BIT(HCLGE_VECTOR0_IMPRESET_INT_B);
+		break;
+	case HNAE3_GLOBAL_RESET:
+		clearval = BIT(HCLGE_VECTOR0_GLOBALRESET_INT_B);
+		break;
+	case HNAE3_CORE_RESET:
+		clearval = BIT(HCLGE_VECTOR0_CORERESET_INT_B);
+		break;
+	default:
+		dev_warn(&hdev->pdev->dev, "Unsupported reset event to clear:%d",
+			 hdev->reset_type);
+		break;
+	}
+
+	if (!clearval)
+		return;
+
+	hclge_write_dev(&hdev->hw, HCLGE_MISC_RESET_STS_REG, clearval);
+	hclge_enable_vector(&hdev->misc_vector, true);
+}
+
 static void hclge_reset(struct hclge_dev *hdev)
 {
 	/* perform reset of the stack & ae device for a client */
@@ -2789,6 +2818,8 @@ static void hclge_reset(struct hclge_dev
 		hclge_reset_ae_dev(hdev->ae_dev);
 		hclge_notify_client(hdev, HNAE3_INIT_CLIENT);
 		rtnl_unlock();
+
+		hclge_clear_reset_cause(hdev);
 	} else {
 		/* schedule again to check pending resets later */
 		set_bit(hdev->reset_type, &hdev->reset_pending);
@@ -5662,9 +5693,6 @@ static int hclge_reset_ae_dev(struct hna
 		return ret;
 	}
 
-	/* Enable MISC vector(vector0) */
-	hclge_enable_vector(&hdev->misc_vector, true);
-
 	dev_info(&pdev->dev, "Reset done, %s driver initialization finished.\n",
 		 HCLGE_DRIVER_NAME);