diff --git a/drivers/net/phy/mdio-bcm-unimac.c b/drivers/net/phy/mdio-bcm-unimac.c
index 08e0647b85e2..8d370667fa1b 100644
--- a/drivers/net/phy/mdio-bcm-unimac.c
+++ b/drivers/net/phy/mdio-bcm-unimac.c
@@ -205,6 +205,8 @@ static int unimac_mdio_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!r)
+		return -EINVAL;
 
 	/* Just ioremap, as this MDIO block is usually integrated into an
 	 * Ethernet MAC controller register range