[RFC PATCH dpss_eth] Don't initialise ports with no PHY

[Darren Stevens <darren@stevens-zone.net>]

Since cbb961ca271e ("Use random MAC address when none is given")
Varisys Cyrus P5020 boards have been listing 5 ethernet ports instead of
the 2 the board has.This is because we were preventing the adding of the
unused ports by not suppling them a MAC address, which this patch now
supplies.

Prevent them from appearing in the net devices list by checking for a
'status="disabled"' entry during probe and skipping the port if we find
it. 

Signed-off-by: Darren Stevens <Darren@stevens-zone.net>

---

 drivers/net/ethernet/freescale/fman/mac.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/net/ethernet/freescale/fman/mac.c b/drivers/net/ethernet/freescale/fman/mac.c
index 43427c5..c9ed411 100644
--- a/drivers/net/ethernet/freescale/fman/mac.c
+++ b/drivers/net/ethernet/freescale/fman/mac.c
@@ -606,6 +606,7 @@ static int mac_probe(struct platform_device *_of_dev)
 	struct resource		 res;
 	struct mac_priv_s	*priv;
 	const u8		*mac_addr;
+	const char 		*prop;
 	u32			 val;
 	u8			fman_id;
 	phy_interface_t          phy_if;
@@ -628,6 +629,16 @@ static int mac_probe(struct platform_device *_of_dev)
 	mac_dev->priv = priv;
 	priv->dev = dev;
 
+	/* check for disabled devices and skip them, as now a missing
+	 * MAC address will be replaced with a Random one rather than
+	 * disabling the port
+	 */
+	prop = of_get_property(mac_node, "status", NULL);
+	if (prop && !strncmp(prop, "disabled", 8) {
+		err = -ENODEV;
+		goto _return
+	}
+
 	if (of_device_is_compatible(mac_node, "fsl,fman-dtsec")) {
 		setup_dtsec(mac_dev);
 		priv->internal_phy_node = of_parse_phandle(mac_node,