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

On 2018/9/20 22:50, Haiyang Zhang wrote:

quoted

-----Original Message-----
From: Stephen Hemminger <stephen@networkplumber.org>
Sent: Thursday, September 20, 2018 10:44 AM
To: YueHaibing <redacted>
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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 [off-list ref] wrote:

quoted

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;

Thank you for review.

Will do that in v2.

Thanks,
- Haiyang

.