[PATCH net 3/5] net: hns3: fix a deadlock problem when config TC during resetting

[Jijie Shao]

From: Jie Wang <wangjie125@xxxxxxxxxx>

When config TC during the reset process, may cause a deadlock, the flow is
as below:
                             pf reset start
                                 │
                                 ▼
                              ......
setup tc                         │
    │                            ▼
    ▼                      DOWN: napi_disable()
napi_disable()(skip)             │
    │                            │
    ▼                            ▼
  ......                      ......
    │                            │
    ▼                            │
napi_enable()                    │
                                 ▼
                           UINIT: netif_napi_del()
                                 │
                                 ▼
                              ......
                                 │
                                 ▼
                           INIT: netif_napi_add()
                                 │
                                 ▼
                              ......                 global reset start
                                 │                      │
                                 ▼                      ▼
                           UP: napi_enable()(skip)    ......
                                 │                      │
                                 ▼                      ▼
                              ......                 napi_disable()

In reset process, the driver will DOWN the port and then UINIT, in this
case, the setup tc process will UP the port before UINIT, so cause the
problem. Adds a DOWN process in UINIT to fix it.

Fixes: bb6b94a896d4 ("net: hns3: Add reset interface implementation in client")
Signed-off-by: Jie Wang <wangjie125@xxxxxxxxxx>
Signed-off-by: Jijie Shao <shaojijie@xxxxxxxxxx>
---
 drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
index a5fc0209d628..4cbc4d069a1f 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
@@ -5724,6 +5724,9 @@ static int hns3_reset_notify_uninit_enet(struct hnae3_handle *handle)
 	struct net_device *netdev = handle->kinfo.netdev;
 	struct hns3_nic_priv *priv = netdev_priv(netdev);
 
+	if (!test_bit(HNS3_NIC_STATE_DOWN, &priv->state))
+		hns3_nic_net_stop(netdev);
+
 	if (!test_and_clear_bit(HNS3_NIC_STATE_INITED, &priv->state)) {
 		netdev_warn(netdev, "already uninitialized\n");
 		return 0;
-- 
2.33.0