hi , question function of net_rx(struct net_device *dev)
hi :
the source code of net_rx(struct net_device *dev) is:
http://lxr.oss.org.cn/source/drivers/net/ethernet/cirrus/cs89x0.c#L670
I can't understand codes about malloc buffer.
##########################################
684 /* Malloc up new buffer. */
685 skb = netdev_alloc_skb(dev, length + 2);
686 if (skb == NULL) {687 dev->stats.rx_dropped++;
688 return;
689 }
690 skb_reserve(skb, 2); /* longword align L3 header */
##########################################
How to explain 'length + 2' in line of 685? Why add 2 ?
Thank you.
Quoted 9 lines · lx
hi :
the source code ofnet_rx(struct net_device *dev)is:
http://lxr.oss.org.cn/source/drivers/net/ethernet/cirrus/cs89x0.c#L670I can't understand codes about malloc buffer.
##########################################684 /* Malloc up new buffer. */ 685 skb = netdev_alloc_skb(dev, length + 2); 686 if (skb == NULL) {
Quoted 7 lines
687 dev->stats.rx_dropped++;
688 return;
689 }
690skb_reserve(skb, 2); /* longword align L3 header */
##########################################How to explain 'length + 2' in line of 685? Why add 2 ?
That's why it's explained on the line 690.
http://lwn.net/Articles/89597/
Quoted 8 lines
Thank you.
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Signature · 2 lines
Regards, Denis