ixgbe: fix for 82599 erratum on Header Splitting

commit a124339a upstream.

We have found a hardware erratum on 82599 hardware that can lead to
unpredictable behavior when Header Splitting mode is enabled.  So
we are no longer enabling this feature on affected hardware.

Please see the 82599 Specification Update for more information.
Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Tested-by: Stephen Ko <stephen.s.ko@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/net/ixgbe/ixgbe_main.c

@@ -2912,10 +2912,17 @@ static void ixgbe_set_rx_buffer_len(struct ixgbe_adapter *adapter)
 	u32 mhadd, hlreg0;
 
 	/* Decide whether to use packet split mode or not */
-	/* Do not use packet split if we're in SR-IOV Mode */
-	if (!adapter->num_vfs)
+	/* On by default */
 	adapter->flags |= IXGBE_FLAG_RX_PS_ENABLED;
 
+	/* Do not use packet split if we're in SR-IOV Mode */
+	if (adapter->num_vfs)
+		adapter->flags &= ~IXGBE_FLAG_RX_PS_ENABLED;
+
+	/* Disable packet split due to 82599 erratum #45 */
+	if (hw->mac.type == ixgbe_mac_82599EB)
+		adapter->flags &= ~IXGBE_FLAG_RX_PS_ENABLED;
+
 	/* Set the RX buffer length according to the mode */
 	if (adapter->flags & IXGBE_FLAG_RX_PS_ENABLED) {
 		rx_buf_len = IXGBE_RX_HDR_SIZE;