On Thu, Feb 7, 2013 at 12:11 PM, 기상원 (SW Ki) <oprsystem@xxxxxxxxxxxxx> wrote: > hello everyone. > > i would like to use our hardware TCP/IP Checksum logic on the mac80211 driver. > but, i can see the IP Checksum in Tx skb_buffer on mac80211 tx handler after "g_ieee80211_hw->netdev_features = NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM;" > > you can find the IP checksum value that is 0x26, 0x42. > [ 40.970000] queue_skb: IP protocol: 0x00000008 > 0xC042382E: 88 01 00 00 00 50 43 21 22 2B 00 01 02 03 04 05 .....PC!"+...... > 0xC042392E: 00 19 B9 79 2D 7E 90 00 00 00 AA AA 03 00 00 00 ...y-~.......... > 0xC0423A2E: 08 00 45 00 00 54 00 00 40 00 40 01 [26 42] 0A 00 ..E..T..@.@.&B.. > 0xC0423B2E: 00 04 0A 00 00 64 08 00 CB C5 CB 02 00 01 F0 33 .....d.........3 > 0xC0423C2E: 71 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 q............... > 0xC0423D2E: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 0xC0423E2E: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 0xC0423F2E: 00 00 00 00 00 00 > > how can I remove the IP checksum field calculation by software generation on mac80211 stack? > > thanks & best regards > Sangwon, Ki > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-wireless" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html The TCP/IP checksum is calcualted by linux network stack. It does the below check and decides to go for checksum or not. skb->ip_summed= CHECKSUM_UNNECESSARY will disable the checksum calculation by linux stack. Your HW can appends its own checksum. Good detailed info on http://www.mail-archive.com/netdev@xxxxxxxxxxxxxxx/msg17044.html ============== static inline int skb_csum_unnecessary(const struct sk_buff *skb) { return skb->ip_summed & CHECKSUM_UNNECESSARY; } -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
