[PATCH 4.16 11/64] hv_netvsc: Fix a network regression after ifdown/ifup

Greg Kroah-Hartman
2018-06-24T15:32:01Z

From: Dexuan Cui <decui@microsoft.com>

[ Upstream commit 52acf73b6e9a6962045feb2ba5a8921da2201915 ]

Recently people reported the NIC stops working after
"ifdown eth0; ifup eth0". It turns out in this case the TX queues are not
enabled, after the refactoring of the common detach logic: when the NIC
has sub-channels, usually we enable all the TX queues after all
sub-channels are set up: see rndis_set_subchannel() ->
netif_device_attach(), but in the case of "ifdown eth0; ifup eth0" where
the number of channels doesn't change, we also must make sure the TX queues
are enabled. The patch fixes the regression.

Fixes: 7b2ee50c0cd5 ("hv_netvsc: common detach logic")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/hyperv/netvsc_drv.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -126,8 +126,10 @@ static int netvsc_open(struct net_device
}

rdev = nvdev->extension;
- if (!rdev->link_state)
+ if (!rdev->link_state) {
netif_carrier_on(net);
+ netif_tx_wake_all_queues(net);
+ }

if (vf_netdev) {
/* Setting synthetic device up transparently sets