igb: Workaround for igb i210 firmware issue

commit 4e684f59 upstream.

Sometimes firmware may not properly initialize I347AT4_PAGE_SELECT causing
the probe of an igb i210 NIC to fail. This patch adds an addition zeroing
of this register during igb_get_phy_id to workaround this issue.

Thanks for Jochen Henneberg for the idea and original patch.
Signed-off-by: Chris J Arges <christopherarges@gmail.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/net/ethernet/intel/igb/e1000_phy.c

@@ -83,6 +83,10 @@ s32 igb_get_phy_id(struct e1000_hw *hw)
 	s32 ret_val = 0;
 	u16 phy_id;
 
+	/* ensure PHY page selection to fix misconfigured i210 */
+	if (hw->mac.type == e1000_i210)
+		phy->ops.write_reg(hw, I347AT4_PAGE_SELECT, 0);
+
 	ret_val = phy->ops.read_reg(hw, PHY_ID1, &phy_id);
 	if (ret_val)
 		goto out;