On Mon, Oct 21, 2019 at 05:49:00PM +0200, Andrew Lunn wrote: > > +static struct sk_buff *ar9331_tag_rcv(struct sk_buff *skb, > > + struct net_device *ndev, > > + struct packet_type *pt) > > +{ > > + u8 ver, port; > > + u16 hdr; > > + > > + if (unlikely(!pskb_may_pull(skb, AR9331_HDR_LEN))) > > + return NULL; > > + > > + hdr = le16_to_cpu(*(__le16 *)skb_mac_header(skb)); > > + > > + ver = FIELD_GET(AR9331_HDR_VERSION_MASK, hdr); > > + if (unlikely(ver != AR9331_HDR_VERSION)) { > > + netdev_warn_once(ndev, "%s:%i wrong header version 0x%2x\n", > > + __func__, __LINE__, hdr); > > + return NULL; > > + } > > + > > + if (unlikely(hdr & AR9331_HDR_FROM_CPU)) { > > + netdev_warn_once(ndev, "%s:%i packet should not be from cpu 0x%2x\n", > > + __func__, __LINE__, hdr); > > + return NULL; > > + } > > + > > + skb_pull(skb, AR9331_HDR_LEN); > > + skb_set_mac_header(skb, -ETH_HLEN); > > No other tag driver calls skb_set_mac_header(). Also, the -ETH_HLEN > looks odd, give you have just pulled off AR9331_HDR_LEN? Hm.. is it corrected somewhere else? Any way, B.T.M.A.N need a proper value ant it seems to work correctly. So I remove it. > What other tag drivers use is skb_pull_rcsum(). It is build in switch and internal Ethernet controller do not set csum. There is nothing to recalculate... on other hand, it adds no overhead. So, I have nothing against it. Are there other arguments? Regards, Oleksij -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |