From: Huazhong Tan <tanhuazhong@huawei.com>
Date: Fri, 28 Jun 2019 19:50:14 +0800
Subject: net: hns3: handle empty unknown interrupt
Patch-mainline: v5.3-rc1
Git-commit: 9bc6ac918c7176fcc306f3e57a34e7bc51ae470c
References: bsc#1104353 FATE#326415

Since some MSI-X interrupt's status may be cleared by hardware,
so when the driver receives the interrupt, reading
HCLGE_VECTOR0_PF_OTHER_INT_STS_REG register will get an empty
unknown interrupt. For this case, the irq handler should enable
vector0 interrupt. This patch also use dev_info() instead of
dev_dbg() in the hclge_check_event_cause(), since this information
will be useful for normal usage.

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_main.c |   15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
@@ -2447,8 +2447,9 @@ static u32 hclge_check_event_cause(struc
 
 	/* check for vector0 msix event source */
 	if (msix_src_reg & HCLGE_VECTOR0_REG_MSIX_MASK) {
-		dev_dbg(&hdev->pdev->dev, "received event 0x%x\n",
-			msix_src_reg);
+		dev_info(&hdev->pdev->dev, "received event 0x%x\n",
+			 msix_src_reg);
+		*clearval = msix_src_reg;
 		return HCLGE_VECTOR0_EVENT_ERR;
 	}
 
@@ -2460,8 +2461,11 @@ static u32 hclge_check_event_cause(struc
 	}
 
 	/* print other vector0 event source */
-	dev_dbg(&hdev->pdev->dev, "cmdq_src_reg:0x%x, msix_src_reg:0x%x\n",
-		cmdq_src_reg, msix_src_reg);
+	dev_info(&hdev->pdev->dev,
+		 "CMDQ INT status:0x%x, other INT status:0x%x\n",
+		 cmdq_src_reg, msix_src_reg);
+	*clearval = msix_src_reg;
+
 	return HCLGE_VECTOR0_EVENT_OTHER;
 }
 
@@ -2540,7 +2544,8 @@ static irqreturn_t hclge_misc_irq_handle
 	}
 
 	/* clear the source of interrupt if it is not cause by reset */
-	if (event_cause == HCLGE_VECTOR0_EVENT_MBX) {
+	if (!clearval ||
+	    event_cause == HCLGE_VECTOR0_EVENT_MBX) {
 		hclge_clear_event_cause(hdev, event_cause, clearval);
 		hclge_enable_vector(&hdev->misc_vector, true);
 	}