[PATCH 4.9 09/59] net: hns: add netif_carrier_off before change speed and duplex

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Peng Li <lipeng...@huawei.com>

[ Upstream commit 455c4401fe7a538facaffb35b906ce19f1ece474 ]

If there are packets in hardware when changing the speed
or duplex, it may cause hardware hang up.

This patch adds netif_carrier_off before change speed and
duplex in ethtool_ops.set_link_ksettings, and adds
netif_carrier_on after complete the change.

Signed-off-by: Peng Li <lipeng...@huawei.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Sasha Levin <alexander.le...@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/net/ethernet/hisilicon/hns/hns_ethtool.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c
+++ b/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c
@@ -243,7 +243,9 @@ static int hns_nic_set_link_ksettings(st
        }
 
        if (h->dev->ops->adjust_link) {
+               netif_carrier_off(net_dev);
                h->dev->ops->adjust_link(h, (int)speed, cmd->base.duplex);
+               netif_carrier_on(net_dev);
                return 0;
        }