| From f6f13c125e05603f68f5bf31f045b95e6d493598 Mon Sep 17 00:00:00 2001 |
| From: Haiyang Zhang <haiyangz@microsoft.com> |
| Date: Fri, 21 Feb 2020 08:32:18 -0800 |
| Subject: hv_netvsc: Fix unwanted wakeup in netvsc_attach() |
| |
| 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"); |
