[azure][PATCH v1 4/9] hv_netvsc: Fix the carrier state error when data path is off

[Marcelo Henrique Cerri]

From: Haiyang Zhang <haiyangz at microsoft.com>

BugLink: http://bugs.launchpad.net/bugs/1708469

When the VF NIC is opened, the synthetic NIC's carrier state is set to
off. This tells the host to transitions data path to the VF device. But
if startup script or user manipulates the admin state of the netvsc
device directly for example:
        # ifconfig eth0 down
	# ifconfig eth0 up
Then the carrier state of the synthetic NIC would be on, even though the
data path was still over the VF NIC. This patch sets the carrier state
of synthetic NIC with consideration of the related VF state.

Signed-off-by: Haiyang Zhang <haiyangz at microsoft.com>
Reviewed-by: Stephen Hemminger <sthemmin at microsoft.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
(cherry picked from commit 53fa1a6f33520f01f9dbee48369074b34d77616b)
Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri at canonical.com>
---
 drivers/net/hyperv/hyperv_net.h | 2 ++
 drivers/net/hyperv/netvsc.c     | 2 ++
 drivers/net/hyperv/netvsc_drv.c | 8 +++++---
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index 880572765b5d..27b71b701e2d 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -722,6 +722,8 @@ struct net_device_context {
 	u32 vf_alloc;
 	/* Serial number of the VF to team with */
 	u32 vf_serial;
+
+	bool datapath;	/* 0 - synthetic, 1 - VF nic */
 };
 
 /* Per channel data */
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 6a2f295d94df..de3aa1cb2611 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -60,6 +60,8 @@ void netvsc_switch_datapath(struct net_device *ndev, bool vf)
 			       sizeof(struct nvsp_message),
 			       (unsigned long)init_pkt,
 			       VM_PKT_DATA_INBAND, 0);
+
+	net_device_ctx->datapath = vf;
 }
 
 static struct netvsc_device *alloc_net_device(void)
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 1825929db52a..c506033c0c1b 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -76,7 +76,8 @@ static void netvsc_set_multicast_list(struct net_device *net)
 
 static int netvsc_open(struct net_device *net)
 {
-	struct netvsc_device *nvdev = net_device_to_netvsc_device(net);
+	struct net_device_context *ndev_ctx = netdev_priv(net);
+	struct netvsc_device *nvdev = ndev_ctx->nvdev;
 	struct rndis_device *rdev;
 	int ret = 0;
 
@@ -92,7 +93,7 @@ static int netvsc_open(struct net_device *net)
 	netif_tx_wake_all_queues(net);
 
 	rdev = nvdev->extension;
-	if (!rdev->link_state)
+	if (!rdev->link_state && !ndev_ctx->datapath)
 		netif_carrier_on(net);
 
 	return ret;
@@ -1317,7 +1318,8 @@ static void netvsc_link_change(struct work_struct *w)
 	case RNDIS_STATUS_MEDIA_CONNECT:
 		if (rdev->link_state) {
 			rdev->link_state = false;
-			netif_carrier_on(net);
+			if (!ndev_ctx->datapath)
+				netif_carrier_on(net);
 			netif_tx_wake_all_queues(net);
 		} else {
 			notify = true;
-- 
2.7.4