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authorVladimir Oltean <vladimir.oltean@nxp.com>2023-12-13 17:27:12 +0200
committerJakub Kicinski <kuba@kernel.org>2023-12-14 18:55:38 -0800
commit10ad63da5c036b2fd61600b43217cfa9b4d66f52 (patch)
tree7b5786fcc83a53d84185f21795ec90e85362ba00 /drivers/net/mdio
parentd215ab4d6ae8bea8f66a50399745791b7de5b7d8 (diff)
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 <vladimir.oltean@nxp.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://lore.kernel.org/r/20231213152712.320842-3-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/mdio')
-rw-r--r--drivers/net/mdio/mdio-mux.c6
1 files 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)