RE: [PATCH net-next 1/9] net: hns3: Add support of HNS3 Ethernet Driver for hip08 SoC

From: Mintz, Yuval
Date: Wed Jun 14 2017 - 04:04:30 EST


> > > +static void hns3_nic_net_down(struct net_device *ndev) {
> > > + struct hns3_nic_priv *priv = netdev_priv(ndev);
> > > + struct hnae3_ae_ops *ops;
> > > + int i;
> > > +
> > > + netif_tx_stop_all_queues(ndev);
> > > + netif_carrier_off(ndev);
> > > + netif_tx_disable(ndev);
> > > +
> > > + ops = priv->ae_handle->ae_algo->ops;
> > > +
> > > + if (ops->stop)
> > > + ops->stop(priv->ae_handle);
> > > +
> > > + netif_tx_stop_all_queues(ndev);
> >
> > Looks a bit excessive. Why do you need all these
> > netif_tx_stop_all_queues()?
> If we are disabling the netdev. We need to stop scheduling the queues
> associated with that netdev for TX, so we need this code. Why do you think
> it is excessive?

Why do you need both netif_tx_disable() and netif_tx_stop_all_queues()?
And why would you need to re-do netif_tx_stop_all_queues() after
calling ops->stop()?

> > Isn't mqprio going to override your priority2tc mapping with the one
> > provided by user?
> I guess you are referring to below code in the mqprio_init() - right?
>
> static int mqprio_init(struct Qdisc *sch, struct nlattr *opt)
> {
> [...]
> /* Always use supplied priority mappings */
> for (i = 0; i < TC_BITMASK + 1; i++)
> netdev_set_prio_tc_map(dev, i, qopt->prio_tc_map[i]);
> [...]
> }
>
> In this case yes, you are right below code seems to be redundant:
>
> + /* Assign UP2TC map for the VSI */
> + for (i = 0; i < HNAE3_MAX_TC; i++) {
> + netdev_set_prio_tc_map(ndev,
> + kinfo->tc_info[i].up,
> + kinfo->tc_info[i].tc);
>
> Hope I am not missing anything here?
You're not; That's what I meant.