jme: Don't show UDP Checksum error if HW misjudged

Some JMicron Chip treat 0 as error checksum for UDP packets.
Which should be "No checksum needed".

Reported-by: Adam Swift <Adam.Swift@omnitude.net>
Confirmed-by: "Aries Lee" <arieslee@jmicron.com>
Signed-off-by: Guo-Fu Tseng <cooldavid@cooldavid.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/jme.c b/drivers/net/jme.c
index ed35e17..5b441b7 100644 (file)
--- a/drivers/net/jme.c
+++ b/drivers/net/jme.c
@@ -956,8 +956,34 @@ jme_disable_rx_engine(struct jme_adapter *jme)
        jme_mac_rxclk_off(jme);
 }
 
+static u16
+jme_udpsum(struct sk_buff *skb)
+{
+       u16 csum = 0xFFFFu;
+
+       if (skb->len < (ETH_HLEN + sizeof(struct iphdr)))
+               return csum;
+       if (skb->protocol != htons(ETH_P_IP))
+               return csum;
+       skb_set_network_header(skb, ETH_HLEN);
+       if ((ip_hdr(skb)->protocol != IPPROTO_UDP) ||
+           (skb->len < (ETH_HLEN +
+                       (ip_hdr(skb)->ihl << 2) +
+                       sizeof(struct udphdr)))) {
+               skb_reset_network_header(skb);
+               return csum;
+       }
+       skb_set_transport_header(skb,
+                       ETH_HLEN + (ip_hdr(skb)->ihl << 2));
+       csum = udp_hdr(skb)->check;
+       skb_reset_transport_header(skb);
+       skb_reset_network_header(skb);
+
+       return csum;
+}
+
 static int
-jme_rxsum_ok(struct jme_adapter *jme, u16 flags)
+jme_rxsum_ok(struct jme_adapter *jme, u16 flags, struct sk_buff *skb)
 {
        if (!(flags & (RXWBFLAG_TCPON | RXWBFLAG_UDPON | RXWBFLAG_IPV4)))
                return false;
@@ -970,7 +996,7 @@ jme_rxsum_ok(struct jme_adapter *jme, u16 flags)
        }
 
        if (unlikely((flags & (RXWBFLAG_MF | RXWBFLAG_UDPON | RXWBFLAG_UDPCS))
-                       == RXWBFLAG_UDPON)) {
+                       == RXWBFLAG_UDPON) && jme_udpsum(skb)) {
                if (flags & RXWBFLAG_IPV4)
                        netif_err(jme, rx_err, jme->dev, "UDP Checksum error\n");
                return false;
@@ -1018,7 +1044,7 @@ jme_alloc_and_feed_skb(struct jme_adapter *jme, int idx)
                skb_put(skb, framesize);
                skb->protocol = eth_type_trans(skb, jme->dev);
 
-               if (jme_rxsum_ok(jme, le16_to_cpu(rxdesc->descwb.flags)))
+               if (jme_rxsum_ok(jme, le16_to_cpu(rxdesc->descwb.flags), skb))
                        skb->ip_summed = CHECKSUM_UNNECESSARY;
                else
                        skb_checksum_none_assert(skb);