pppoe and receive checksum offload

[Stephen Hemminger <shemminger@xxxxxxxx>]

Someone reported a problem with skge hardware receive checksumming and PPPOE
but it looks like a generic problem.  Since PPPOE adds additional header
bytes the hardware computed checksum will be wrong.  

Not sure if this is correct, but shouldn't pppoe be doing the following:
-----
diff -Nru a/drivers/net/pppoe.c b/drivers/net/pppoe.c
--- a/drivers/net/pppoe.c       2005-02-24 15:40:10 -08:00
+++ b/drivers/net/pppoe.c       2005-02-24 15:40:10 -08:00
@@ -339,6 +339,7 @@
                int len = ntohs(ph->length);
                skb_pull(skb, sizeof(struct pppoe_hdr));
                skb_trim(skb, len);
+               skb->ip_summed = CHECKSUM_NONE;
 
                ppp_input(&po->chan, skb);
        } else if (sk->sk_state & PPPOX_RELAY) {