RE: [PATCH net-next 1/3] net/usb/r8152: support aggregation

From: hayeswang
Date: Tue Aug 13 2013 - 08:32:41 EST


Oliver Neukum [mailto:oneukum@xxxxxxx]
> Sent: Tuesday, August 13, 2013 4:49 PM
> To: Hayeswang
> Cc: netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> linux-usb@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH net-next 1/3] net/usb/r8152: support aggregation
>
[...]
> > + len_used = 0;
> > + rx_desc = agg->head;
> > + rx_data = agg->head;
> > + smp_wmb();
> > + pkt_len = le32_to_cpu(rx_desc->opts1) & RX_LEN_MASK;
> > + len_used += sizeof(struct rx_desc) + pkt_len;
> > +
> > + while (urb->actual_length >= len_used) {
> > + if (pkt_len < ETH_ZLEN)
> > + break;
> > +
> > + pkt_len -= 4; /* CRC */
> > + rx_data += sizeof(struct rx_desc);
> > +
> > + skb = netdev_alloc_skb_ip_align(netdev,
> > pkt_len);
> > + if (!skb) {
> > + stats->rx_dropped++;
> > + break;
> > + }
> > + memcpy(skb->data, rx_data, pkt_len);
> > + skb_put(skb, pkt_len);
> > + skb->protocol = eth_type_trans(skb, netdev);
> > + netif_rx(skb);
> > + stats->rx_packets++;
> > + stats->rx_bytes += pkt_len;
> > +
> > + rx_data = rx_agg_align(rx_data +
> pkt_len + 4);
> > + rx_desc = (struct rx_desc *)rx_data;
> > + smp_wmb();
>
> Against what is the memory barrier?

Excuse me. I don't understand your question. Do you mean the function should not
be used here?

Best Regards,
Hayes

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