smsc911x: Ignore error return from device_get_phy_mode()

Commit 62ee783bf1f8 ("smsc911x: Fix crash seen if neither ACPI nor OF is
configured or used") introduces an error check for the return value from
device_get_phy_mode() and bails out if there is an error. Unfortunately,
there are configurations where no phy is configured. Those configurations
now fail.

To fix the problem, accept error returns from device_get_phy_mode(),
and use the return value from device_property_read_u32() to determine
if there is a suitable firmware interface to read the configuration.

Fixes: 62ee783bf1f8 ("smsc911x: Fix crash seen if neither ACPI nor OF is configured or used")
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/smsc/smsc911x.c

@@ -2369,23 +2369,25 @@ static int smsc911x_probe_config(struct smsc911x_platform_config *config,
 {
 	int phy_interface;
 	u32 width = 0;
+	int err;
 
 	phy_interface = device_get_phy_mode(dev);
 	if (phy_interface < 0)
-		return phy_interface;
-
+		phy_interface = PHY_INTERFACE_MODE_NA;
 	config->phy_interface = phy_interface;
 
 	device_get_mac_address(dev, config->mac, ETH_ALEN);
 
-	device_property_read_u32(dev, "reg-shift", &config->shift);
-
-	device_property_read_u32(dev, "reg-io-width", &width);
-	if (width == 4)
+	err = device_property_read_u32(dev, "reg-io-width", &width);
+	if (err == -ENXIO)
+		return err;
+	if (!err && width == 4)
 		config->flags |= SMSC911X_USE_32BIT;
 	else
 		config->flags |= SMSC911X_USE_16BIT;
 
+	device_property_read_u32(dev, "reg-shift", &config->shift);
+
 	if (device_property_present(dev, "smsc,irq-active-high"))
 		config->irq_polarity = SMSC911X_IRQ_POLARITY_ACTIVE_HIGH;