Re: [PATCH net 1/3] net: hns3: fix for TX queue not restarted problem

[David Miller]

From: Yunsheng Lin <linyunsheng@xxxxxxxxxx>
Date: Tue, 3 Dec 2019 12:28:22 +0800

> On 2019/12/3 11:25, David Miller wrote:
>> From: Huazhong Tan <tanhuazhong@xxxxxxxxxx>
>> Date: Tue, 3 Dec 2019 11:08:53 +0800
>> 
>>> diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
>>> index ba05368..b2bb8e2 100644
>>> --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
>>> +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
>>> @@ -1286,13 +1286,16 @@ static bool hns3_skb_need_linearized(struct sk_buff *skb, unsigned int *bd_size,
>>>  	return false;
>>>  }
>>>  
>>> -static int hns3_nic_maybe_stop_tx(struct hns3_enet_ring *ring,
>>> +static int hns3_nic_maybe_stop_tx(struct net_device *netdev,
>>>  				  struct sk_buff **out_skb)
>>>  {
>>> +	struct hns3_nic_priv *priv = netdev_priv(netdev);
>>>  	unsigned int bd_size[HNS3_MAX_TSO_BD_NUM + 1U];
>>>  	struct sk_buff *skb = *out_skb;
>>> +	struct hns3_enet_ring *ring;
>>>  	unsigned int bd_num;
>>>  
>>> +	ring = &priv->ring[skb->queue_mapping];
>> 
>> Please just pass the ring pointer into hns3_nic_maybe_stop_tx() instead of
>> needlessly recalculating it.
> 
> The reason that I am passing the netdev instead of ring pointer is
> that the netif_start_subqueue() need a netdev parameter, and the
> netdev can not be derived from the ring pointer.
> 
> Do you think it is better to keep it as this patch, or add a new
> netdevice parameter? like below:

Just add the netdev parameter, in addition to the ring parameter.

All arguments fit in the register argument passing conventions of
various cpus so the cost of adding the parameter is zero.