net/phy: tune get_phy_c45_ids to support more c45 phy

As some C45 10G PHYs(e.g. Cortina CS4315/CS4340 PHY) have
zero Devices In package, current driver can't get correct
devices_in_package value by non-zero Devices In package.
so let's probe more with zero Devices In package to support
more C45 PHYs.
Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/phy_device.c

@@ -230,7 +230,7 @@ static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id,
 	for (i = 1;
 	     i < num_ids && c45_ids->devices_in_package == 0;
 	     i++) {
-		reg_addr = MII_ADDR_C45 | i << 16 | MDIO_DEVS2;
+retry:		reg_addr = MII_ADDR_C45 | i << 16 | MDIO_DEVS2;
 		phy_reg = mdiobus_read(bus, addr, reg_addr);
 		if (phy_reg < 0)
 			return -EIO;
@@ -242,12 +242,20 @@ static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id,
 			return -EIO;
 		c45_ids->devices_in_package |= (phy_reg & 0xffff);
 
-		/* If mostly Fs, there is no device there,
-		 * let's get out of here.
-		 */
 		if ((c45_ids->devices_in_package & 0x1fffffff) == 0x1fffffff) {
-			*phy_id = 0xffffffff;
-			return 0;
+			if (i) {
+				/*  If mostly Fs, there is no device there,
+				 *  then let's continue to probe more, as some
+				 *  10G PHYs have zero Devices In package,
+				 *  e.g. Cortina CS4315/CS4340 PHY.
+				 */
+				i = 0;
+				goto retry;
+			} else {
+				/* no device there, let's get out of here */
+				*phy_id = 0xffffffff;
+				return 0;
+			}
 		}
 	}