[PATCH net-next 17/22] hv_netvsc: fix return type of ndo_start_xmit function

[Haiyang Zhang]

> -----Original Message-----
> From: Stephen Hemminger <stephen at networkplumber.org>
> Sent: Thursday, September 20, 2018 10:44 AM
> To: YueHaibing <yuehaibing at huawei.com>
> Cc: davem at davemloft.net; dmitry.tarnyagin at lockless.no;
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> Subject: Re: [PATCH net-next 17/22] hv_netvsc: fix return type of
> ndo_start_xmit function
> 
> On Thu, 20 Sep 2018 20:33:01 +0800
> YueHaibing <yuehaibing at huawei.com> wrote:
> > int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
> >  	 */
> >  	vf_netdev = rcu_dereference_bh(net_device_ctx->vf_netdev);
> >  	if (vf_netdev && netif_running(vf_netdev) &&
> > -	    !netpoll_tx_running(net))
> > -		return netvsc_vf_xmit(net, vf_netdev, skb);
> > +	    !netpoll_tx_running(net)) {
> > +		ret = netvsc_vf_xmit(net, vf_netdev, skb);
> > +		if (ret)
> > +			return NETDEV_TX_BUSY;
> > +	}
> 
> Sorry, the new code is wrong. It will fall through if ret == 0 (NETDEV_TX_OK)
> Please review and test your patches.

Plus consideration of -- For error case, please just return NETDEV_TX_OK. We 
are not sure if the error can go away after retrying, returning NETDEV_TX_BUSY 
may cause infinite retry from the upper layer.

So, let's just always return NETDEV_TX_OK like this:
		netvsc_vf_xmit(net, vf_netdev, skb);
		return NETDEV_TX_OK;

Thanks,
- Haiyang