linux-stable.git/drivers/net/mdio, branch linux-5.15.y

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

2026-01-19T12:09:56+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: aspeed: move reg accessing part into separate functions

2026-01-19T12:09:56+00:00

[ Upstream commit 737ca352569e744bf753b4522a6f91b120a734f1 ]

Add aspeed_mdio_op() and aseed_mdio_get_data() for register accessing.

aspeed_mdio_op() handles operations, write command to control register,
then check and wait operations is finished (bit 31 is cleared).

aseed_mdio_get_data() fetchs the result value of operation from data
register.

Signed-off-by: Potin Lai 
Reviewed-by: Andrew Lunn 
Signed-off-by: David S. Miller 
Stable-dep-of: d1a1a4bade4b ("net: mdio: aspeed: add dummy read to avoid read-after-write issue")
Signed-off-by: Sasha Levin

net: mdiobus: fix an OF node reference leak

2025-01-09T12:28:32+00:00

[ Upstream commit 572af9f284669d31d9175122bbef9bc62cea8ded ]

fwnode_find_mii_timestamper() calls of_parse_phandle_with_fixed_args()
but does not decrement the refcount of the obtained OF node. Add an
of_node_put() call before returning from the function.

This bug was detected by an experimental static analysis tool that I am
developing.

Fixes: bc1bee3b87ee ("net: mdiobus: Introduce fwnode_mdiobus_register_phy()")
Signed-off-by: Joe Hattori 
Reviewed-by: Andrew Lunn 
Link: https://patch.msgid.link/20241218035106.1436405-1-joe@pf.is.s.u-tokyo.ac.jp
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

net: mdio-ipq4019: add missing error check

2024-12-14T18:51:09+00:00

[ Upstream commit 9cc8d0ecdd2aad42e377e971e3bb114339df609e ]

If an optional resource is found but fails to remap, return on failure.
Avoids any potential problems when using the iomapped resource as the
assumption is that it's available.

Fixes: 23a890d493e3 ("net: mdio: Add the reset function for IPQ MDIO driver")
Signed-off-by: Rosen Penev 
Reviewed-by: Andrew Lunn 
Link: https://patch.msgid.link/20241121193152.8966-1-rosenp@gmail.com
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

net: mdio: mvusb: Fix an error handling path in mvusb_mdio_probe()

2023-05-24T16:36:41+00:00

[ Upstream commit 27c1eaa07283b0c94becf8241f95368267cf558b ]

Should of_mdiobus_register() fail, a previous usb_get_dev() call should be
undone as in the .disconnect function.

Fixes: 04e37d92fbed ("net: phy: add marvell usb to mdio controller")
Signed-off-by: Christophe JAILLET 
Reviewed-by: Simon Horman 
Reviewed-by: Andrew Lunn 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: mdio: thunder: Add missing fwnode_handle_put()

2023-03-30T10:47:50+00:00

[ Upstream commit b1de5c78ebe9858ccec9d49af2f76724f1d47e3e ]

In device_for_each_child_node(), we should add fwnode_handle_put()
when break out of the iteration device_for_each_child_node()
as it will automatically increase and decrease the refcounter.

Fixes: 379d7ac7ca31 ("phy: mdio-thunder: Add driver for Cavium Thunder SoC MDIO buses.")
Signed-off-by: Liang He 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: mdio: fix owner field for mdio buses registered using ACPI

2023-03-30T10:47:46+00:00

[ Upstream commit 30b605b8501e321f79e19c3238aa6ca31da6087c ]

Bus ownership is wrong when using acpi_mdiobus_register() to register an
mdio bus. That function is not inline, so when it calls
mdiobus_register() the wrong THIS_MODULE value is captured.

CC: Maxime Bizon 
Fixes: 803ca24d2f92 ("net: mdio: Add ACPI support code for mdio")
Signed-off-by: Florian Fainelli 
Reviewed-by: Simon Horman 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: mdio: fix owner field for mdio buses registered using device-tree

2023-03-30T10:47:46+00:00

[ Upstream commit 99669259f3361d759219811e670b7e0742668556 ]

Bus ownership is wrong when using of_mdiobus_register() to register an mdio
bus. That function is not inline, so when it calls mdiobus_register() the wrong
THIS_MODULE value is captured.

Signed-off-by: Maxime Bizon 
Fixes: 90eff9096c01 ("net: phy: Allow splitting MDIO bus/device support from PHYs")
[florian: fix kdoc, added Fixes tag]
Signed-off-by: Florian Fainelli 
Reviewed-by: Simon Horman 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: mdio-mux-meson-g12a: force internal PHY off on mux switch

2023-02-01T07:27:29+00:00

[ Upstream commit 7083df59abbc2b7500db312cac706493be0273ff ]

Force the internal PHY off then on when switching to the internal path.
This fixes problems where the PHY ID is not properly set.

Fixes: 7090425104db ("net: phy: add amlogic g12a mdio mux support")
Suggested-by: Qi Duan 
Co-developed-by: Heiner Kallweit 
Signed-off-by: Heiner Kallweit 
Signed-off-by: Jerome Brunet 
Link: https://lore.kernel.org/r/20230124101157.232234-1-jbrunet@baylibre.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

net: mdio: fix unbalanced fwnode reference count in mdio_device_release()

2022-12-14T10:37:28+00:00

[ Upstream commit cb37617687f2bfa5b675df7779f869147c9002bd ]

There is warning report about of_node refcount leak
while probing mdio device:

OF: ERROR: memory leak, expected refcount 1 instead of 2,
of_node_get()/of_node_put() unbalanced - destroy cset entry:
attach overlay node /spi/soc@0/mdio@710700c0/ethernet@4

In of_mdiobus_register_device(), we increase fwnode refcount
by fwnode_handle_get() before associating the of_node with
mdio device, but it has never been decreased in normal path.
Since that, in mdio_device_release(), it needs to call
fwnode_handle_put() in addition instead of calling kfree()
directly.

After above, just calling mdio_device_free() in the error handle
path of of_mdiobus_register_device() is enough to keep the
refcount balanced.

Fixes: a9049e0c513c ("mdio: Add support for mdio drivers.")
Signed-off-by: Zeng Heng 
Reviewed-by: Yang Yingliang 
Reviewed-by: Russell King (Oracle) 
Link: https://lore.kernel.org/r/20221203073441.3885317-1-zengheng4@huawei.com
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin