[PATCH 3/3] net: xilinx: Force a probe failure if it cannot setup phy

[Andy Chiu]

Or we may get load access faults afterward.

The `phydev` field on axi-ethernet’s private struct is not set on a
failed phy_connect():

axi_emac_probe()
=> axiemac_phy_init()
   => priv->phydev = phy_connect() <--- may fail

However, all of the following calls on `axi_emac_ops` assume a valid
`phydev` pointer. For example:

axiemac_start()
=> setup_phy()
   => phy_startup()
      => if (phydev->drv->startup) <--- deref of phydev
           return phydev->drv->startup(phydev);

Thus, it would be better to fail at the driver probe and let u-boot
handle the rest (e.g. probe the driver again if needed), rather than
having access faults.

Signed-off-by: Andy Chiu <andy.chiu at sifive.com>
Reviewed-by: Greentime Hu <greentime.hu at sifive.com>
---

 drivers/net/xilinx_axi_emac.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/net/xilinx_axi_emac.c b/drivers/net/xilinx_axi_emac.c
index dbda6c70d8..08322aff88 100644
--- a/drivers/net/xilinx_axi_emac.c
+++ b/drivers/net/xilinx_axi_emac.c
@@ -782,10 +782,16 @@ static int axiemac_setup_emac(struct udevice *dev)
 
 	ret = mdio_register_seq(priv->bus, dev_seq(dev));
 	if (ret)
-		return ret;
+		goto fail;
 
-	axiemac_phy_init(dev);
+	ret = axiemac_phy_init(dev);
+	if (ret)
+		goto fail_free_mdio;
 
+fail_free_mdio:
+	mdio_unregister(priv->bus);
+	mdio_free(priv->bus);
+fail:
 	return ret;
 }
 
-- 
2.34.1