From d215ab4d6ae8bea8f66a50399745791b7de5b7d8 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Wed, 13 Dec 2023 17:27:11 +0200 Subject: [PATCH 1/2] net: mdio-mux: show errors on probe failure Showing the precise error symbols can help debugging probe issues, such as the recent -EIO error in of_mdiobus_register() caused by the lack of bus->read_c45() and bus->write_c45() methods. Signed-off-by: Vladimir Oltean Reviewed-by: Andrew Lunn Link: https://lore.kernel.org/r/20231213152712.320842-2-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski --- drivers/net/mdio/mdio-mux.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/net/mdio/mdio-mux.c b/drivers/net/mdio/mdio-mux.c index bef4cce71287..e5dee7ad7c09 100644 --- a/drivers/net/mdio/mdio-mux.c +++ b/drivers/net/mdio/mdio-mux.c @@ -190,8 +190,8 @@ int mdio_mux_init(struct device *dev, r = of_property_read_u32(child_bus_node, "reg", &v); if (r) { dev_err(dev, - "Error: Failed to find reg for child %pOF\n", - child_bus_node); + "Error: Failed to find reg for child %pOF: %pe\n", + child_bus_node, ERR_PTR(r)); continue; } @@ -229,8 +229,8 @@ int mdio_mux_init(struct device *dev, } devm_kfree(dev, cb); dev_err(dev, - "Error: Failed to register MDIO bus for child %pOF\n", - child_bus_node); + "Error: Failed to register MDIO bus for child %pOF: %pe\n", + child_bus_node, ERR_PTR(r)); } else { cb->next = pb->children; pb->children = cb; From 10ad63da5c036b2fd61600b43217cfa9b4d66f52 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Wed, 13 Dec 2023 17:27:12 +0200 Subject: [PATCH 2/2] net: mdio-mux: be compatible with parent buses which only support C45 After the mii_bus API conversion to a split read() / read_c45(), there might be MDIO parent buses which only populate the read_c45() and write_c45() function pointers but not the C22 variants. We haven't seen these in the wild paired with MDIO multiplexers, but Andrew points out we should treat the corner case. Link: https://lore.kernel.org/netdev/4ccd7dc9-b611-48aa-865f-68d3a1327ce8@lunn.ch/ Signed-off-by: Vladimir Oltean Reviewed-by: Andrew Lunn Link: https://lore.kernel.org/r/20231213152712.320842-3-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski --- drivers/net/mdio/mdio-mux.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/mdio/mdio-mux.c b/drivers/net/mdio/mdio-mux.c index e5dee7ad7c09..fe0e46bd7964 100644 --- a/drivers/net/mdio/mdio-mux.c +++ b/drivers/net/mdio/mdio-mux.c @@ -214,8 +214,10 @@ int mdio_mux_init(struct device *dev, snprintf(cb->mii_bus->id, MII_BUS_ID_SIZE, "%s-%x.%x", cb->mii_bus->name, pb->parent_id, v); cb->mii_bus->parent = dev; - cb->mii_bus->read = mdio_mux_read; - cb->mii_bus->write = mdio_mux_write; + if (parent_bus->read) + cb->mii_bus->read = mdio_mux_read; + if (parent_bus->write) + cb->mii_bus->write = mdio_mux_write; if (parent_bus->read_c45) cb->mii_bus->read_c45 = mdio_mux_read_c45; if (parent_bus->write_c45)