[BNX2]: Block MII access when ifdown.

The device may be in D3hot state and should not allow MII register
access.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
index f98a220..9f0a067 100644
--- a/drivers/net/bnx2.c
+++ b/drivers/net/bnx2.c
@@ -5562,6 +5562,9 @@
 	case SIOCGMIIREG: {
 		u32 mii_regval;
 
+		if (!netif_running(dev))
+			return -EAGAIN;
+
 		spin_lock_bh(&bp->phy_lock);
 		err = bnx2_read_phy(bp, data->reg_num & 0x1f, &mii_regval);
 		spin_unlock_bh(&bp->phy_lock);
@@ -5575,6 +5578,9 @@
 		if (!capable(CAP_NET_ADMIN))
 			return -EPERM;
 
+		if (!netif_running(dev))
+			return -EAGAIN;
+
 		spin_lock_bh(&bp->phy_lock);
 		err = bnx2_write_phy(bp, data->reg_num & 0x1f, data->val_in);
 		spin_unlock_bh(&bp->phy_lock);