of: of_mdio: Correct loop scanning logic

[ Upstream commit 5a8d7f126c97d04d893f5e5be2b286437a0d01b0 ]

Commit 209c65b61d94 ("drivers/of/of_mdio.c:fix of_mdiobus_register()")
introduced a break of the loop on the premise that a successful
registration should exit the loop. The premise is correct but not to
code, because rc && rc != -ENODEV is just a special error condition,
that means we would exit the loop even with rc == -ENODEV which is
absolutely not correct since this is the error code to indicate to the
MDIO bus layer that scanning should continue.

Fix this by explicitly checking for rc = 0 as the only valid condition
to break out of the loop.

Fixes: 209c65b61d94 ("drivers/of/of_mdio.c:fix of_mdiobus_register()")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
index 69da2f6896dae5261533ad11dcddfc75a002119d..8b7d3e64b8cab66faf8b500b5fcaf58801300de3 100644 (file)
--- a/drivers/of/of_mdio.c
+++ b/drivers/of/of_mdio.c
@@ -256,10 +256,15 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
                                 child->name, addr);
 
                        if (of_mdiobus_child_is_phy(child)) {
+                               /* -ENODEV is the return code that PHYLIB has
+                                * standardized on to indicate that bus
+                                * scanning should continue.
+                                */
                                rc = of_mdiobus_register_phy(mdio, child, addr);
-                               if (rc && rc != -ENODEV)
+                               if (!rc)
+                                       break;
+                               if (rc != -ENODEV)
                                        goto unregister;
-                               break;
                        }
                }
        }