igb: change how we handle alternate mac addresses

This patch allows us to treat the alternate mac address as though it is the
physical address on the adapter.  This is accomplished by letting the
alt_mac_address function to only fail on an NVM error.  If no errors occur
and the alternate mac address is not present then RAR0 is read as the
default mac address.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 8 deletions

diff --git a/drivers/net/igb/e1000_mac.c b/drivers/net/igb/e1000_mac.c
index 986aa902f7ed..4969a5b1cf3c 100644
--- a/drivers/net/igb/e1000_mac.c
+++ b/drivers/net/igb/e1000_mac.c
@@ -185,13 +185,12 @@ s32 igb_check_alt_mac_addr(struct e1000_hw *hw)
 	}
 
 	if (nvm_alt_mac_addr_offset == 0xFFFF) {
-		ret_val = -(E1000_NOT_IMPLEMENTED);
+		/* There is no Alternate MAC Address */
 		goto out;
 	}
 
 	if (hw->bus.func == E1000_FUNC_1)
-		nvm_alt_mac_addr_offset += ETH_ALEN/sizeof(u16);
-
+		nvm_alt_mac_addr_offset += E1000_ALT_MAC_ADDRESS_OFFSET_LAN1;
 	for (i = 0; i < ETH_ALEN; i += 2) {
 		offset = nvm_alt_mac_addr_offset + (i >> 1);
 		ret_val = hw->nvm.ops.read(hw, offset, 1, &nvm_data);
@@ -206,14 +205,16 @@ s32 igb_check_alt_mac_addr(struct e1000_hw *hw)
 
 	/* if multicast bit is set, the alternate address will not be used */
 	if (alt_mac_addr[0] & 0x01) {
-		ret_val = -(E1000_NOT_IMPLEMENTED);
+		hw_dbg("Ignoring Alternate Mac Address with MC bit set\n");
 		goto out;
 	}
 
-	for (i = 0; i < ETH_ALEN; i++)
-		hw->mac.addr[i] = hw->mac.perm_addr[i] = alt_mac_addr[i];
-
-	hw->mac.ops.rar_set(hw, hw->mac.perm_addr, 0);
+	/*
+	 * We have a valid alternate MAC address, and we want to treat it the
+	 * same as the normal permanent MAC address stored by the HW into the
+	 * RAR. Do this by mapping this address into RAR0.
+	 */
+	hw->mac.ops.rar_set(hw, alt_mac_addr, 0);
 
 out:
 	return ret_val;