e1000e: specify max supported frame size in adapter struct

By putting the maximum frame size supported by the hardware into the
adapter structure, the change_mtu entry point function can be cleaned
up of checks for all the different max frame sizes supported by

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/e1000e/82571.c b/drivers/net/e1000e/82571.c
index 6c01a207..8203964 100644
--- a/drivers/net/e1000e/82571.c
+++ b/drivers/net/e1000e/82571.c
@@ -341,8 +341,10 @@
 			if (e1000_read_nvm(&adapter->hw, NVM_INIT_3GIO_3, 1,
 				       &eeprom_data) < 0)
 				break;
-			if (eeprom_data & NVM_WORD1A_ASPM_MASK)
-				adapter->flags &= ~FLAG_HAS_JUMBO_FRAMES;
+			if (!(eeprom_data & NVM_WORD1A_ASPM_MASK)) {
+				adapter->flags |= FLAG_HAS_JUMBO_FRAMES;
+				adapter->max_hw_frame_size = DEFAULT_JUMBO;
+			}
 		}
 		break;
 	default:
@@ -1672,6 +1674,7 @@
 				  | FLAG_TARC_SPEED_MODE_BIT /* errata */
 				  | FLAG_APME_CHECK_PORT_B,
 	.pba			= 38,
+	.max_hw_frame_size	= DEFAULT_JUMBO,
 	.get_variants		= e1000_get_variants_82571,
 	.mac_ops		= &e82571_mac_ops,
 	.phy_ops		= &e82_phy_ops_igp,
@@ -1688,6 +1691,7 @@
 				  | FLAG_HAS_CTRLEXT_ON_LOAD
 				  | FLAG_TARC_SPEED_MODE_BIT, /* errata */
 	.pba			= 38,
+	.max_hw_frame_size	= DEFAULT_JUMBO,
 	.get_variants		= e1000_get_variants_82571,
 	.mac_ops		= &e82571_mac_ops,
 	.phy_ops		= &e82_phy_ops_igp,
@@ -1706,6 +1710,7 @@
 				  | FLAG_HAS_ERT
 				  | FLAG_HAS_SWSM_ON_LOAD,
 	.pba			= 20,
+	.max_hw_frame_size	= ETH_FRAME_LEN + ETH_FCS_LEN,
 	.get_variants		= e1000_get_variants_82571,
 	.mac_ops		= &e82571_mac_ops,
 	.phy_ops		= &e82_phy_ops_m88,
@@ -1724,6 +1729,7 @@
 				  | FLAG_HAS_AMT
 				  | FLAG_HAS_CTRLEXT_ON_LOAD,
 	.pba			= 20,
+	.max_hw_frame_size	= ETH_FRAME_LEN + ETH_FCS_LEN,
 	.get_variants		= e1000_get_variants_82571,
 	.mac_ops		= &e82571_mac_ops,
 	.phy_ops		= &e82_phy_ops_bm,
@@ -1740,6 +1746,7 @@
 				  | FLAG_HAS_AMT
 				  | FLAG_HAS_CTRLEXT_ON_LOAD,
 	.pba			= 20,
+	.max_hw_frame_size	= DEFAULT_JUMBO,
 	.get_variants		= e1000_get_variants_82571,
 	.mac_ops		= &e82571_mac_ops,
 	.phy_ops		= &e82_phy_ops_bm,