Hi Yuval,

> -----Original Message-----
> From: Mintz, Yuval [mailto:yuval.mi...@cavium.com]
> Sent: Wednesday, June 14, 2017 9:04 AM
> To: Salil Mehta; da...@davemloft.net
> Cc: Zhuangyuzeng (Yisen); huangdaode; lipeng (Y);
> mehta.salil....@gmail.com; net...@vger.kernel.org; linux-
> ker...@vger.kernel.org; Linuxarm
> Subject: RE: [PATCH net-next 1/9] net: hns3: Add support of HNS3
> Ethernet Driver for hip08 SoC
> 
> > > > +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()?
Oh yes! I missed this totally, In fact, netif_tx_diable is doing almost
the similar job what netif_tx_stop_all_queues() is doing with some
lock protection.

Thanks for identifying this. I will fix this in V3 patch. 

Thanks
Salil
> 
> > > 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.
Will remove this code in V3 patch.

Thanks
Salil


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