net: mdio-mux: fix C45 access returning -EIO after API change
authorVladimir Oltean <vladimir.oltean@nxp.com>
Tue, 17 Oct 2023 14:31:44 +0000 (17:31 +0300)
committerJakub Kicinski <kuba@kernel.org>
Thu, 19 Oct 2023 01:08:23 +0000 (18:08 -0700)
commit1f9f2143f24e224a8582a5d54918c43b9121eccc
tree8592accc70ed34b9919eff9bea3512701fb2c3ee
parentf921a4a5bffa8a0005b190fb9421a7fc1fd716b6
net: mdio-mux: fix C45 access returning -EIO after API change

The mii_bus API conversion to read_c45() and write_c45() did not cover
the mdio-mux driver before read() and write() were made C22-only.

This broke arch/arm64/boot/dts/freescale/fsl-ls1028a-qds-13bb.dtso.
The -EOPNOTSUPP from mdiobus_c45_read() is transformed by
get_phy_c45_devs_in_pkg() into -EIO, is further propagated to
of_mdiobus_register() and this makes the mdio-mux driver fail to probe
the entire child buses, not just the PHYs that cause access errors.

Fix the regression by introducing special c45 read and write accessors
to mdio-mux which forward the operation to the parent MDIO bus.

Fixes: db1a63aed89c ("net: phy: Remove fallback to old C45 method")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://lore.kernel.org/r/20231017143144.3212657-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
drivers/net/mdio/mdio-mux.c