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    SubjectRe: [PATCH v2] net: add Faraday FTMAC100 10/100 Ethernet driver
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    On Mon, 2011-01-17 at 18:29 +0100, Eric Dumazet wrote:
    > Le lundi 17 janvier 2011 à 17:21 +0800, Po-Yu Chuang a écrit :
    >
    >
    > > +static int ftmac100_rx_packet(struct ftmac100 *priv, int *processed)
    > > +{
    > > + struct net_device *netdev = priv->netdev;
    > > + struct ftmac100_rxdes *rxdes;
    > > + struct sk_buff *skb;
    > > + int length;
    > > + int copied = 0;
    > > + int done = 0;
    > > +
    > > + rxdes = ftmac100_rx_locate_first_segment(priv);
    > > + if (!rxdes)
    > > + return 0;
    > > +
    > > + length = ftmac100_rxdes_frame_length(rxdes);
    > > +
    > > + netdev->stats.rx_packets++;
    > > + netdev->stats.rx_bytes += length;
    > > +
    > > + if (unlikely(ftmac100_rx_packet_error(priv, rxdes))) {
    > > + ftmac100_rx_drop_packet(priv);
    > > + return 1;
    > > + }
    > > +
    > > + /* start processing */
    > > + skb = netdev_alloc_skb_ip_align(netdev, length);
    > > + if (unlikely(!skb)) {
    > > + if (net_ratelimit())
    > > + netdev_err(netdev, "rx skb alloc failed\n");
    > > +
    > > + ftmac100_rx_drop_packet(priv);
    > > + return 1;
    > > + }
    > > +
    >
    > Please dont increase rx_packets/rx_bytes before the
    > netdev_alloc_skb_ip_align().
    >
    > In case of mem allocation failure, it would be better not pretending we
    > handled a packet.
    >
    > drivers/net/r8169.c for example does the rx_packets/rx_bytes only if
    > packet is delivered to upper stack.

    That's news to me. I specifically advised Po-Yu Chuang to increment
    these earlier because my understanding is that all packets/bytes should
    be counted. And drivers which use hardware MAC stats will generally do
    that, so I really don't think it makes sense to make other drivers
    different deliberately.

    Ben.

    --
    Ben Hutchings, Senior Software Engineer, Solarflare Communications
    Not speaking for my employer; that's the marketing department's job.
    They asked us to note that Solarflare product names are trademarked.

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