kernel/linux.git/drivers/net/mdio, branch v6.18.21

net: mdio: rtl9300: use scoped for loops

2026-01-08T09:16:47+00:00

[ Upstream commit a4f800c4487dc5d6fcc28da89c7cc3c187ccc731 ] Currently in the return path, fwnode_handle_put calls are missing. Just use _scoped to avoid the issue. Fixes: 24e31e474769 ("net: mdio: Add RTL9300 MDIO driver") Signed-off-by: Rosen Penev Link: https://patch.msgid.link/20251217210153.14641-1-rosenp@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net: mdio: aspeed: add dummy read to avoid read-after-write issue

2026-01-08T09:16:44+00:00

[ Upstream commit d1a1a4bade4b20c0858d0b2f81d2611de055f675 ] The Aspeed MDIO controller may return incorrect data when a read operation follows immediately after a write. Due to a controller bug, the subsequent read can latch stale data, causing the polling logic to terminate earlier than expected. To work around this hardware issue, insert a dummy read after each write operation. This ensures that the next actual read returns the correct data and prevents premature polling exit. This workaround has been verified to stabilize MDIO transactions on affected Aspeed platforms. Fixes: f160e99462c6 ("net: phy: Add mdio-aspeed") Signed-off-by: Jacky Chou Reviewed-by: Andrew Lunn Link: https://patch.msgid.link/20251211-aspeed_mdio_add_dummy_read-v3-1-382868869004@aspeedtech.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net: mdio: Check regmap pointer returned by device_node_to_regmap()

2025-11-04T00:20:03+00:00

The call to device_node_to_regmap() in airoha_mdio_probe() can return an ERR_PTR() if regmap initialization fails. Currently, the driver stores the pointer without validation, which could lead to a crash if it is later dereferenced. Add an IS_ERR() check and return the corresponding error code to make the probe path more robust. Fixes: 67e3ba978361 ("net: mdio: Add MDIO bus controller for Airoha AN7583") Signed-off-by: Alok Tiwari Reviewed-by: Andrew Lunn Link: https://patch.msgid.link/20251031161607.58581-1-alok.a.tiwari@oracle.com Signed-off-by: Jakub Kicinski

net: mdio: mdio-i2c: Hold the i2c bus lock during smbus transactions

2025-10-07T08:44:46+00:00

When accessing an MDIO register using single-byte smbus accesses, we have to perform 2 consecutive operations targeting the same address, first accessing the MSB then the LSB of the 16 bit register: read_1_byte(addr); <- returns MSB of register at address 'addr' read_1_byte(addr); <- returns LSB Some PHY devices present in SFP such as the Broadcom 5461 don't like seeing foreign i2c transactions in-between these 2 smbus accesses, and will return the MSB a second time when trying to read the LSB : read_1_byte(addr); <- returns MSB i2c_transaction_for_other_device_on_the_bus(); read_1_byte(addr); <- returns MSB again Given the already fragile nature of accessing PHYs/SFPs with single-byte smbus accesses, it's safe to say that this Broadcom PHY may not be the only one acting like this. Let's therefore hold the i2c bus lock while performing our smbus transactions to avoid interleaved accesses. Fixes: d4bd3aca33c2 ("net: mdio: mdio-i2c: Add support for single-byte SMBus operations") Signed-off-by: Maxime Chevallier Reviewed-by: Kory Maincent Reviewed-by: Andrew Lunn Link: https://patch.msgid.link/20251003070311.861135-1-maxime.chevallier@bootlin.com Signed-off-by: Paolo Abeni

net: phy: move config symbol MDIO_BUS to drivers/net/phy/Kconfig

2025-09-23T23:56:27+00:00

Config symbol MDIO_BUS isn't used in drivers/net/mdio. It's only used in drivers/net/phy. So move it there. Signed-off-by: Heiner Kallweit Link: https://patch.msgid.link/164ff1c6-2cf9-4e30-80fb-da4cc7165dc8@gmail.com Signed-off-by: Jakub Kicinski

of: mdio: warn if deprecated fixed-link binding is used

2025-09-16T01:15:41+00:00

The array-style fixed-link binding has been marked deprecated for more than 10 yrs, but still there's a number of users. Print a warning when usage of the deprecated binding is detected. Signed-off-by: Heiner Kallweit Reviewed-by: Andrew Lunn Link: https://patch.msgid.link/faf94844-96eb-400f-8a3a-b2a0e93b27d7@gmail.com Signed-off-by: Jakub Kicinski

net: phy: fixed_phy: let fixed_phy_unregister free the phy_device

2025-08-27T00:19:40+00:00

fixed_phy_register() creates and registers the phy_device. To be symmetric, we should not only unregister, but also free the phy_device in fixed_phy_unregister(). This allows to simplify code in users. Note wrt of_phy_deregister_fixed_link(): put_device(&phydev->mdio.dev) and phy_device_free(phydev) are identical. Signed-off-by: Heiner Kallweit Reviewed-by: Russell King (Oracle) Link: https://patch.msgid.link/ad8dda9a-10ed-4060-916b-3f13bdbb899d@gmail.com Signed-off-by: Jakub Kicinski

net: mdio: mdio-bcm-unimac: Refine incorrect clock message

2025-08-13T00:16:20+00:00

In light of a81649a4efd3 ("net: mdio: mdio-bcm-unimac: Correct rate fallback logic"), it became clear that the warning should be specific to the MDIO controller instance, and there should be further information provided to indicate what is wrong, whether the requested clock frequency or the rate calculation. Clarify the message accordingly. Signed-off-by: Florian Fainelli Link: https://patch.msgid.link/20250811165921.392030-1-florian.fainelli@broadcom.com Signed-off-by: Jakub Kicinski

net: mdio: mdio-bcm-unimac: Correct rate fallback logic

2025-08-01T21:46:50+00:00

When the parent clock is a gated clock which has multiple parents, the clock provider (clk-scmi typically) might return a rate of 0 since there is not one of those particular parent clocks that should be chosen for returning a rate. Prior to ee975351cf0c ("net: mdio: mdio-bcm-unimac: Manage clock around I/O accesses"), we would not always be passing a clock reference depending upon how mdio-bcm-unimac was instantiated. In that case, we would take the fallback path where the rate is hard coded to 250MHz. Make sure that we still fallback to using a fixed rate for the divider calculation, otherwise we simply ignore the desired MDIO bus clock frequency which can prevent us from interfacing with Ethernet PHYs properly. Fixes: ee975351cf0c ("net: mdio: mdio-bcm-unimac: Manage clock around I/O accesses") Signed-off-by: Florian Fainelli Reviewed-by: Andrew Lunn Reviewed-by: Simon Horman Link: https://patch.msgid.link/20250730202533.3463529-1-florian.fainelli@broadcom.com Signed-off-by: Jakub Kicinski

net: mdio: Add MDIO bus controller for Airoha AN7583

2025-06-27T09:09:36+00:00

Airoha AN7583 SoC have 2 dedicated MDIO bus controller in the SCU register map. To driver register an MDIO controller based on the DT reg property and access the register by accessing the parent syscon. The MDIO bus logic is similar to the MT7530 internal MDIO bus but deviates of some setting and some HW bug. On Airoha AN7583 the MDIO clock is set to 25MHz by default and needs to be correctly setup to 2.5MHz to correctly work (by setting the divisor to 10x). There seems to be Hardware bug where AN7583_MII_RWDATA is not wiped in the context of unconnected PHY and the previous read value is returned. Example: (only one PHY on the BUS at 0x1f) - read at 0x1f report at 0x2 0x7500 - read at 0x0 report 0x7500 on every address To workaround this, we reset the Mdio BUS at every read to have consistent values on read operation. Signed-off-by: Christian Marangi Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller