[PATCH] hv_netvsc: Fix a network regression after ifdown/ifup
From: Dexuan Cui
Date: Wed Jun 06 2018 - 17:02:15 EST
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. The patch fixes
the regression.
Fixes: 7b2ee50c0cd5 ("hv_netvsc: common detach logic")
Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Cc: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
Cc: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
---
drivers/net/hyperv/netvsc_drv.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index da07ccd..4461e16 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -126,9 +126,20 @@ static int netvsc_open(struct net_device *net)
}
rdev = nvdev->extension;
- if (!rdev->link_state)
+ if (!rdev->link_state) {
netif_carrier_on(net);
+ /* 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.
+ */
+ if (atomic_read(&nvdev->open_chn) == nvdev->num_chn)
+ netif_tx_wake_all_queues(net);
+ }
+
if (vf_netdev) {
/* Setting synthetic device up transparently sets
* slave as up. If open fails, then slave will be
--
2.7.4