sky2: fix checksum bit management on some chips

[ Upstream commit 5ff0feac88ced864f44adb145142269196fa79d9 ]

The newer flavors of Yukon II use a different method for receive
checksum offload. This is indicated in the driver by the SKY2_HW_NEW_LE
flag. On these newer chips, the BMU_ENA_RX_CHKSUM should not be set.

The driver would get incorrectly toggle the bit, enabling the old
checksum logic on these chips and cause a BUG_ON() assertion. If
receive checksum was toggled via ethtool.

Reported-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 6 insertions, 4 deletions

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index f2e31c87d9f..9d4a2a38545 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -4206,10 +4206,12 @@ static int sky2_set_features(struct net_device *dev, u32 features)
         struct sky2_port *sky2 = netdev_priv(dev);
         u32 changed = dev->features ^ features;
 
-        if (changed & NETIF_F_RXCSUM) {
-                u32 on = features & NETIF_F_RXCSUM;
-                sky2_write32(sky2->hw, Q_ADDR(rxqaddr[sky2->port], Q_CSR),
-                             on ? BMU_ENA_RX_CHKSUM : BMU_DIS_RX_CHKSUM);
+        if ((changed & NETIF_F_RXCSUM) &&
+            !(sky2->hw->flags & SKY2_HW_NEW_LE)) {
+                sky2_write32(sky2->hw,
+                             Q_ADDR(rxqaddr[sky2->port], Q_CSR),
+                             (features & NETIF_F_RXCSUM)
+                             ? BMU_ENA_RX_CHKSUM : BMU_DIS_RX_CHKSUM);
         }
 
         if (changed & NETIF_F_RXHASH)