On Tue, Sep 24, 2019 at 4:47 PM Grant Grundler <grund...@chromium.org> wrote:
>
> On Mon, Sep 23, 2019 at 7:47 PM Hayes Wang <hayesw...@realtek.com> wrote:
> >
> > Prashant Malani [mailto:pmal...@chromium.org]
> > > Sent: Tuesday, September 24, 2019 6:27 AM
> > > To: Hayes Wang
> > [...]
> > > - do {
> > > + while (1) {
> > > struct tx_agg *agg;
> > > + struct net_device *netdev = tp->netdev;
> > >
> > > if (skb_queue_empty(&tp->tx_queue))
> > > break;
> > > @@ -2188,26 +2189,25 @@ static void tx_bottom(struct r8152 *tp)
> > > break;
> > >
> > > res = r8152_tx_agg_fill(tp, agg);
> > > - if (res) {
> > > - struct net_device *netdev = tp->netdev;
> > > + if (!res)
> > > + break;
> >
> > I let the loop run continually until an error occurs or the queue is empty.
> > However, you stop the loop when r8152_tx_agg_fill() is successful.
>
> Hayes,
> Are you sure about both assertions?
> The do/while loop exits if "res == 0". Isn't that the same as "!res"?
Hayes,
Sorry, You are correct.
thanks,
grant
>
> > If an error occurs continually, the loop may not be broken.
>
> And what prevents that from happening with the current code?
>
> Should current code break out of the loop in -ENODEV case, right?
>
> That would be more obvious if the code inside the loop were:
> ...
> res = r8152_tx_agg_fill(tp, agg);
> if (res == -ENODEV) {
> ...
> break;
> }
> if (!res)
> break;
> ...
>
> (Or whatever the right code is to "loop until an error occurs or queue
> is empty").
>
> cheers,
> grant
>
> >
> > > - if (res == -ENODEV) {
> > > - rtl_set_unplug(tp);
> > > - netif_device_detach(netdev);
> > > - } else {
> > > - struct net_device_stats *stats =
> > > &netdev->stats;
> > > - unsigned long flags;
> > > + if (res == -ENODEV) {
> > > + rtl_set_unplug(tp);
> > > + netif_device_detach(netdev);
> > > + } else {
> > > + struct net_device_stats *stats = &netdev->stats;
> > > + unsigned long flags;
> > >
> > > - netif_warn(tp, tx_err, netdev,
> > > - "failed tx_urb %d\n", res);
> > > - stats->tx_dropped += agg->skb_num;
> > > + netif_warn(tp, tx_err, netdev,
> > > + "failed tx_urb %d\n", res);
> > > + stats->tx_dropped += agg->skb_num;
> > >
> > > - spin_lock_irqsave(&tp->tx_lock, flags);
> > > - list_add_tail(&agg->list, &tp->tx_free);
> > > - spin_unlock_irqrestore(&tp->tx_lock, flags);
> > > - }
> > > + spin_lock_irqsave(&tp->tx_lock, flags);
> > > + list_add_tail(&agg->list, &tp->tx_free);
> > > + spin_unlock_irqrestore(&tp->tx_lock, flags);
> > > }
> > > - } while (res == 0);
> > > + }
> >
> > I think the behavior is different from the current one.
> >
> > Best Regards,
> > Hayes
> >
