Subject: [PATCH AUTOSEL 4.18 08/39] net: hns3: bugfix for rtnl_lock's range in the hclge_reset()

From: Sasha Levin <[email-masked]>
Date: Tue, 13 Nov 2018 00:50:22 -0500

From: Huazhong Tan <[email-masked]>

[ Upstream commit a963052e539887df481d4d3a6ad4c92ca6461852 ]

Since hclge_reset_wait() is used to wait for the hardware to complete
the reset, it is not necessary to hold the rtnl_lock during
hclge_reset_wait(). So this patch releases the lock for the duration
of hclge_reset_wait().

Fixes: 6d4fab39533f ("net: hns3: Reset net device with rtnl_lock")
Signed-off-by: Huazhong Tan <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
index 13f43b74fd6d..de85a31106e7 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
@@ -2827,14 +2827,17 @@ static void hclge_reset(struct hclge_dev *hdev)
 	/* perform reset of the stack & ae device for a client */
 	rtnl_lock();
 	hclge_notify_client(hdev, HNAE3_DOWN_CLIENT);
+	rtnl_unlock();
 
 	if (!hclge_reset_wait(hdev)) {
+		rtnl_lock();
 		hclge_notify_client(hdev, HNAE3_UNINIT_CLIENT);
 		hclge_reset_ae_dev(hdev->ae_dev);
 		hclge_notify_client(hdev, HNAE3_INIT_CLIENT);
 
 		hclge_clear_reset_cause(hdev);
 	} else {
+		rtnl_lock();
 		/* schedule again to check pending resets later */
 		set_bit(hdev->reset_type, &hdev->reset_pending);
 		hclge_reset_task_schedule(hdev);
-- 
2.17.1