On Fri, 4 Sep 2020 19:52:18 -0700 Dexuan Cui wrote:
> mlx5_suspend()/resume() keep the network interface, so during hibernation
> netvsc_unregister_vf() and netvsc_register_vf() are not called, and hence
> netvsc_resume() should call netvsc_vf_changed() to switch the data path
> back to the VF after hibernation.
Does suspending the system automatically switch back to the synthetic
datapath? Please clarify this in the commit message and/or add a code
comment.
> Similarly, netvsc_suspend() should not call netvsc_unregister_vf().
>
> BTW, mlx4_suspend()/resume() are differnt in that they destroy and
> re-create the network device, so netvsc_register_vf() and
> netvsc_unregister_vf() are automatically called. Note: mlx4 can also work
> with the changes here because in netvsc_suspend()/resume()
> ndev_ctx->vf_netdev is NULL for mlx4.
>
> Fixes: 0efeea5fb153 ("hv_netvsc: Add the support of hibernation")
> Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
> ---
> drivers/net/hyperv/netvsc_drv.c | 11 ++++++-----
> 1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
> index 64b0a74c1523..f896059a9588 100644
> --- a/drivers/net/hyperv/netvsc_drv.c
> +++ b/drivers/net/hyperv/netvsc_drv.c
> @@ -2587,7 +2587,7 @@ static int netvsc_remove(struct hv_device *dev)
> static int netvsc_suspend(struct hv_device *dev)
> {
> struct net_device_context *ndev_ctx;
> - struct net_device *vf_netdev, *net;
> + struct net_device *net;
> struct netvsc_device *nvdev;
> int ret;
Please keep reverse xmas tree variable ordering.
> @@ -2604,10 +2604,6 @@ static int netvsc_suspend(struct hv_device *dev)
> goto out;
> }
>
> - vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
> - if (vf_netdev)
> - netvsc_unregister_vf(vf_netdev);
> -
> /* Save the current config info */
> ndev_ctx->saved_netvsc_dev_info = netvsc_devinfo_get(nvdev);
>
> @@ -2623,6 +2619,7 @@ 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();
> @@ -2635,6 +2632,10 @@ static int netvsc_resume(struct hv_device *dev)
> netvsc_devinfo_put(device_info);
> net_device_ctx->saved_netvsc_dev_info = NULL;
>
> + vf_netdev = rtnl_dereference(net_device_ctx->vf_netdev);
> + if (vf_netdev && netvsc_vf_changed(vf_netdev) != NOTIFY_OK)
> + ret = -EINVAL;
Should you perhaps remove the VF in case of the failure?
> rtnl_unlock();
>
> return ret;
