hv_netvsc: Switch the data path at the right time during hibernation

When netvsc_resume() is called, the mlx5 VF NIC has not been resumed yet,
so in the future the host might sliently fail the call netvsc_vf_changed()
-> netvsc_switch_datapath() there, even if the call works now.

Call netvsc_vf_changed() in the NETDEV_CHANGE event handler: at that time
the mlx5 VF NIC has been resumed.

Fixes: 19162fd4063a ("hv_netvsc: Fix hibernation for mlx5 VF driver")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 81c5c70..4a25886 100644 (file)
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2619,7 +2619,6 @@ static int netvsc_resume(struct hv_device *dev)
        struct net_device *net = hv_get_drvdata(dev);
        struct net_device_context *net_device_ctx;
        struct netvsc_device_info *device_info;
-       struct net_device *vf_netdev;
        int ret;
 
        rtnl_lock();
@@ -2632,15 +2631,6 @@ static int netvsc_resume(struct hv_device *dev)
        netvsc_devinfo_put(device_info);
        net_device_ctx->saved_netvsc_dev_info = NULL;
 
-       /* A NIC driver (e.g. mlx5) may keep the VF network interface across
-        * hibernation, but here the data path is implicitly switched to the
-        * netvsc NIC since the vmbus channel is closed and re-opened, so
-        * netvsc_vf_changed() must be used to switch the data path to the VF.
-        */
-       vf_netdev = rtnl_dereference(net_device_ctx->vf_netdev);
-       if (vf_netdev && netvsc_vf_changed(vf_netdev) != NOTIFY_OK)
-               ret = -EINVAL;
-
        rtnl_unlock();
 
        return ret;
@@ -2701,6 +2691,7 @@ static int netvsc_netdev_event(struct notifier_block *this,
                return netvsc_unregister_vf(event_dev);
        case NETDEV_UP:
        case NETDEV_DOWN:
+       case NETDEV_CHANGE:
                return netvsc_vf_changed(event_dev);
        default:
                return NOTIFY_DONE;