sky2: no jumbo on Yukon FE

The Yukon FE (100mbit only) chips do not support large packets.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index 4d1ec78..6950b2d 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -1899,6 +1899,9 @@
 	if (new_mtu < ETH_ZLEN || new_mtu > ETH_JUMBO_MTU)
 		return -EINVAL;
 
+	if (new_mtu > ETH_DATA_LEN && hw->chip_id == CHIP_ID_YUKON_FE)
+		return -EINVAL;
+
 	if (!netif_running(dev)) {
 		dev->mtu = new_mtu;
 		return 0;