[PATCH net-next v19 04/10] net: phy: Create SFP phy_port before registering upstream

[Maxime Chevallier]

When dealing with PHY-driven SFP, we create a phy_port representing the
SFP bus when we know we have such a bus.

We can move the port creation before registering the sfp upstream ops,
as long as we know the SFP bus is there. This will allow passing the
phy_port along with the upstream information to the SFP bus.

Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
Tested-by: Aleksei Sviridkin <f@xxxxxx>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@xxxxxxxxxx>
Tested-by: Christophe Leroy (CS GROUP) <chleroy@xxxxxxxxxx>
Signed-off-by: Maxime Chevallier <maxime.chevallier@xxxxxxxxxxx>
---
 drivers/net/phy/phy_device.c | 62 ++++++++++++++++++++++++------------
 1 file changed, 42 insertions(+), 20 deletions(-)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index ab1aa8981c00..7713418a6734 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1586,13 +1586,13 @@ static void phy_del_port(struct phy_device *phydev, struct phy_port *port)
 	phydev->n_ports--;
 }
 
-static int phy_setup_sfp_port(struct phy_device *phydev)
+static struct phy_port *phy_setup_sfp_port(struct phy_device *phydev)
 {
 	struct phy_port *port = phy_port_alloc();
 	int ret;
 
 	if (!port)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
 	port->parent_type = PHY_PORT_PHY;
 	port->phy = phydev;
@@ -1607,10 +1607,12 @@ static int phy_setup_sfp_port(struct phy_device *phydev)
 	 * when attaching the port to the phydev.
 	 */
 	ret = phy_add_port(phydev, port);
-	if (ret)
+	if (ret) {
 		phy_port_destroy(port);
+		return ERR_PTR(ret);
+	}
 
-	return ret;
+	return port;
 }
 
 /**
@@ -1619,32 +1621,48 @@ static int phy_setup_sfp_port(struct phy_device *phydev)
  */
 static int phy_sfp_probe(struct phy_device *phydev)
 {
+	struct phy_port *port;
 	struct sfp_bus *bus;
-	int ret = 0;
 
-	if (phydev->mdio.dev.fwnode) {
-		bus = sfp_bus_find_fwnode(phydev->mdio.dev.fwnode);
-		if (IS_ERR(bus))
-			return PTR_ERR(bus);
+	if (!phydev->mdio.dev.fwnode)
+		return 0;
 
-		phydev->sfp_bus = bus;
+	bus = sfp_bus_find_fwnode(phydev->mdio.dev.fwnode);
+	if (IS_ERR(bus))
+		return PTR_ERR(bus);
 
-		ret = sfp_bus_add_upstream(bus, phydev, &sfp_phydev_ops);
-		sfp_bus_put(bus);
+	phydev->sfp_bus = bus;
 
-		if (ret)
+	if (bus) {
+		port = phy_setup_sfp_port(phydev);
+		if (IS_ERR(port)) {
+			sfp_bus_put(bus);
 			phydev->sfp_bus = NULL;
+			return PTR_ERR(port);
+		}
 	}
 
-	if (!ret && phydev->sfp_bus) {
-		ret = phy_setup_sfp_port(phydev);
-		if (ret) {
-			sfp_bus_del_upstream(phydev->sfp_bus);
-			phydev->sfp_bus = NULL;
-		}
+	return 0;
+}
+
+static int phy_sfp_add_upstream(struct phy_device *phydev)
+{
+	struct sfp_bus *bus = phydev->sfp_bus;
+	int ret;
+
+	ret = sfp_bus_add_upstream(bus, phydev, &sfp_phydev_ops);
+	if (ret) {
+		sfp_bus_put(bus);
+		phydev->sfp_bus = NULL;
+		return ret;
 	}
 
-	return ret;
+	/* sfp_bus_add_upstream() grabs a ref to the sfp bus on success, it's
+	 * safe to release it now.
+	 */
+	sfp_bus_put(bus);
+
+	return 0;
 }
 
 /**
@@ -3551,6 +3569,10 @@ static int phy_setup_ports(struct phy_device *phydev)
 			break;
 		}
 
+	ret = phy_sfp_add_upstream(phydev);
+	if (ret)
+		goto err_sfp;
+
 	return 0;
 
 err_sfp:
-- 
2.56.0