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

From: Jijie Shao
Date: Tue Aug 13 2024 - 10:17:14 EST


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