net: stmmac: fix invalid call to mdiobus_get_phy()

[ Upstream commit 1f3bd64ad921f051254591fbed04fd30b306cde6 ]

In a number of cases the driver assigns a default value of -1 to
priv->plat->phy_addr. This may result in calling mdiobus_get_phy()
with addr parameter being -1. Therefore check for this scenario and
bail out before calling mdiobus_get_phy().

Fixes: e08a56c85e3d ("net: stmmac: Fix case when PHY handle is not present")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/669f9671-ecd1-a41b-2727-7b73e3003985@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 9931724c4727d1d2e39c87a896ec74d6a4bcc9c6..3079e52546663b200e5f2175078cd1ce9d49b6f2 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -998,6 +998,11 @@ static int stmmac_init_phy(struct net_device *dev)
                int addr = priv->plat->phy_addr;
                struct phy_device *phydev;
 
+               if (addr < 0) {
+                       netdev_err(priv->dev, "no phy found\n");
+                       return -ENODEV;
+               }
+
                phydev = mdiobus_get_phy(priv->mii, addr);
                if (!phydev) {
                        netdev_err(priv->dev, "no phy at addr %d\n", addr);