tree 259c1cde1578ea0f2981bc9f85a8b0e94d583d04
parent ffab1579f14bfaf7e838a11a34394f34db4c89bb
author Petri Gynther <pgynther@google.com> 1425498685 -0800
committer Petri Gynther <pgynther@google.com> 1425499391 -0800

net: bcmgenet: fix bcmgenet_fixed_phy_link_update()

bcmgenet_fixed_phy_link_update() is getting called from PHY detach path:
  bcmgenet_fixed_phy_link_update()
  fixed_mdio_read()
  mdiobus_read()
  genphy_suspend()
  phy_suspend()
  phy_detach()
  bcmgenet_close()

Looking at phy_detach() code, it does:
  phydev->attached_dev->phydev = NULL;
  phydev->attached_dev = NULL;
  phy_suspend(phydev);

bcmgenet_fixed_phy_link_update() needs to check its function parameters
more carefully before doing anything.

Change-Id: Ic3b888c1cdc4cd9b88fd093a048bfcc856e6809b