[PATCH net 6/7] net: hns3: fix VF reset fail issue

[Jijie Shao]

Currently the reset process in hns3 and firmware watchdog init process is
asynchronous. We think firmware watchdog initialization is completed
before VF clear the interrupt source. However, firmware initialization
may not complete early. So VF will receive multiple reset interrupts
and fail to reset.

So we add delay before VF interrupt source and 5 ms delay
is enough to avoid second reset interrupt.

Fixes: 427900d27d86 ("net: hns3: fix the timing issue of VF clearing interrupt sources")
Signed-off-by: Jijie Shao <shaojijie@xxxxxxxxxx>
---
 .../ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c   | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c b/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c
index 1c62e58ff6d8..7b87da031be6 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c
@@ -1924,8 +1924,14 @@ static void hclgevf_service_task(struct work_struct *work)
 	hclgevf_mailbox_service_task(hdev);
 }
 
-static void hclgevf_clear_event_cause(struct hclgevf_dev *hdev, u32 regclr)
+static void hclgevf_clear_event_cause(struct hclgevf_dev *hdev, u32 regclr,
+				      bool need_dalay)
 {
+#define HCLGEVF_RESET_DELAY		5
+
+	if (need_dalay)
+		mdelay(HCLGEVF_RESET_DELAY);
+
 	hclgevf_write_dev(&hdev->hw, HCLGE_COMM_VECTOR0_CMDQ_SRC_REG, regclr);
 }
 
@@ -1990,7 +1996,8 @@ static irqreturn_t hclgevf_misc_irq_handle(int irq, void *data)
 	hclgevf_enable_vector(&hdev->misc_vector, false);
 	event_cause = hclgevf_check_evt_cause(hdev, &clearval);
 	if (event_cause != HCLGEVF_VECTOR0_EVENT_OTHER)
-		hclgevf_clear_event_cause(hdev, clearval);
+		hclgevf_clear_event_cause(hdev, clearval,
+					  event_cause == HCLGEVF_VECTOR0_EVENT_RST);
 
 	switch (event_cause) {
 	case HCLGEVF_VECTOR0_EVENT_RST:
@@ -2340,7 +2347,7 @@ static int hclgevf_misc_irq_init(struct hclgevf_dev *hdev)
 		return ret;
 	}
 
-	hclgevf_clear_event_cause(hdev, 0);
+	hclgevf_clear_event_cause(hdev, 0, false);
 
 	/* enable misc. vector(vector 0) */
 	hclgevf_enable_vector(&hdev->misc_vector, true);
-- 
2.30.0