Re: [Patch V4 net 01/11] net: hns3: add error handler for hns3_nic_init_vector_data()

[Joe Perches <joe@perches.com>]

On Tue, 2018-10-30 at 09:21 +0800, tanhuazhong wrote:
> 
> On 2018/10/30 1:44, Joe Perches wrote:
> > On Mon, 2018-10-29 at 21:54 +0800, Huazhong Tan wrote:
> > > When hns3_nic_init_vector_data() fails to map ring to vector,
> > > it should cancel the netif_napi_add() that has been successfully
> > > done and then exits.
> > []
> > > diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
> > []
> > > @@ -2821,7 +2821,7 @@ static int hns3_nic_init_vector_data(struct hns3_nic_priv *priv)
> > >   	struct hnae3_handle *h = priv->ae_handle;
> > >   	struct hns3_enet_tqp_vector *tqp_vector;
> > >   	int ret = 0;
> > > -	u16 i;
> > > +	int i, j;
> > >   
> > >   	hns3_nic_set_cpumask(priv);
> > >   
> > > @@ -2868,13 +2868,19 @@ static int hns3_nic_init_vector_data(struct hns3_nic_priv *priv)
> > >   		hns3_free_vector_ring_chain(tqp_vector, &vector_ring_chain);
> > >   
> > >   		if (ret)
> > > -			return ret;
> > > +			goto map_ring_fail;
> > >   
> > >   		netif_napi_add(priv->netdev, &tqp_vector->napi,
> > >   			       hns3_nic_common_poll, NAPI_POLL_WEIGHT);
> > >   	}
> > >   
> > >   	return 0;
> > > +
> > > +map_ring_fail:
> > > +	for (j = i - 1; j >= 0; j--)
> > > +		netif_napi_del(&priv->tqp_vector[j].napi);
> > 
> > style trivia:
> > 
> > Error clearing is most commonly done without another variable
> > by decrementing i in the loop.
> > 
> 
> Hi, Joe.
> Is the below one more suitable?

Yes.

> +
> +map_ring_fail:
> +	while(i--)
> +		netif_napi_del(&priv->tqp_vector[i].napi);
> +
> +	return ret;
> 
> Or do you have any other better suggestion?

No I do not.

"while (i--)" is a much more common style.

cheers, Joe