From: Haiyang Zhang haiyangz@microsoft.com
commit f6f13c125e05603f68f5bf31f045b95e6d493598 upstream.
When netvsc_attach() is called by operations like changing MTU, etc., an extra wakeup may happen while netvsc_attach() calling rndis_filter_device_add() which sends rndis messages when queue is stopped in netvsc_detach(). The completion message will wake up queue 0.
We can reproduce the issue by changing MTU etc., then the wake_queue counter from "ethtool -S" will increase beyond stop_queue counter: stop_queue: 0 wake_queue: 1 The issue causes queue wake up, and counter increment, no other ill effects in current code. So we didn't see any network problem for now.
To fix this, initialize tx_disable to true, and set it to false when the NIC is ready to be attached or registered.
Fixes: 7b2ee50c0cd5 ("hv_netvsc: common detach logic") Signed-off-by: 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.c | 2 +- drivers/net/hyperv/netvsc_drv.c | 3 +++ 2 files changed, 4 insertions(+), 1 deletion(-)
--- a/drivers/net/hyperv/netvsc.c +++ b/drivers/net/hyperv/netvsc.c @@ -99,7 +99,7 @@ static struct netvsc_device *alloc_net_d
init_waitqueue_head(&net_device->wait_drain); net_device->destroy = false; - net_device->tx_disable = false; + net_device->tx_disable = true;
net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT; net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT; --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -977,6 +977,7 @@ static int netvsc_attach(struct net_devi }
/* In any case device is now ready */ + nvdev->tx_disable = false; netif_device_attach(ndev);
/* Note: enable and attach happen when sub-channels setup */ @@ -2354,6 +2355,8 @@ static int netvsc_probe(struct hv_device else net->max_mtu = ETH_DATA_LEN;
+ nvdev->tx_disable = false; + ret = register_netdevice(net); if (ret != 0) { pr_err("Unable to register netdev.\n");