linux-stable.git/drivers/net/phy/mdio_device.c, branch linux-rolling-lts

net: phy: assign default match function for non-PHY MDIO devices

2025-06-13T01:12:37+00:00

Make mdio_device_bus_match() the default match function for non-PHY
MDIO devices. Benefit is that we don't have to export this function
any longer. As long as mdiodev->modalias isn't set, there's no change
in behavior. mdiobus_create_device() is the only place where
mdiodev->modalias gets set, but this function sets
mdio_device_bus_match() as match function anyway.

Signed-off-by: Heiner Kallweit 
Link: https://patch.msgid.link/6c94e3d3-bfb0-4ddc-a518-6fddbc64e1d0@gmail.com
Signed-off-by: Jakub Kicinski

net: phy: make mdio consumer / device layer a separate module

2025-05-20T10:22:47+00:00

After having factored out the provider part from mdio_bus.c, we can
make the mdio consumer / device layer a separate module. This also
allows to remove Kconfig symbol MDIO_DEVICE.
The module init / exit functions from mdio_bus.c no longer have to be
called from phy_device.c. The link order defined in
drivers/net/phy/Makefile ensures that init / exit functions are called
in the right order.

Signed-off-by: Heiner Kallweit 
Link: https://patch.msgid.link/dba6b156-5748-44ce-b5e2-e8dc2fcee5a7@gmail.com
Signed-off-by: Paolo Abeni

driver core: have match() callback in struct bus_type take a const *

2024-07-03T13:16:54+00:00

In the match() callback, the struct device_driver * should not be
changed, so change the function callback to be a const *.  This is one
step of many towards making the driver core safe to have struct
device_driver in read-only memory.

Because the match() callback is in all busses, all busses are modified
to handle this properly.  This does entail switching some container_of()
calls to container_of_const() to properly handle the constant *.

For some busses, like PCI and USB and HV, the const * is cast away in
the match callback as those busses do want to modify those structures at
this point in time (they have a local lock in the driver structure.)
That will have to be changed in the future if they wish to have their
struct device * in read-only-memory.

Cc: Rafael J. Wysocki 
Reviewed-by: Alex Elder 
Acked-by: Sumit Garg 
Link: https://lore.kernel.org/r/2024070136-wrongdoer-busily-01e8@gregkh
Signed-off-by: Greg Kroah-Hartman

net: phy: mdio_device: Reset device only when necessary

2023-12-01T07:11:21+00:00

Currently the phy reset sequence is as shown below for a
devicetree described mdio phy on boot:

1. Assert the phy_device's reset as part of registering
2. Deassert the phy_device's reset as part of registering
3. Deassert the phy_device's reset as part of phy_probe
4. Deassert the phy_device's reset as part of phy_hw_init

The extra two deasserts include waiting the deassert delay afterwards,
which is adding unnecessary delay.

This applies to both possible types of resets (reset controller
reference and a reset gpio) that can be used.

Here's some snipped tracing output using the following command line
params "trace_event=gpio:* trace_options=stacktrace" illustrating
the reset handling and where its coming from:

    /* Assert */
       systemd-udevd-283     [002] .....     6.780434: gpio_value: 544 set 0
       systemd-udevd-283     [002] .....     6.783849: 
     => gpiod_set_raw_value_commit
     => gpiod_set_value_nocheck
     => gpiod_set_value_cansleep
     => mdio_device_reset
     => mdiobus_register_device
     => phy_device_register
     => fwnode_mdiobus_phy_device_register
     => fwnode_mdiobus_register_phy
     => __of_mdiobus_register
     => stmmac_mdio_register
     => stmmac_dvr_probe
     => stmmac_pltfr_probe
     => devm_stmmac_pltfr_probe
     => qcom_ethqos_probe
     => platform_probe

    /* Deassert */
       systemd-udevd-283     [002] .....     6.802480: gpio_value: 544 set 1
       systemd-udevd-283     [002] .....     6.805886: 
     => gpiod_set_raw_value_commit
     => gpiod_set_value_nocheck
     => gpiod_set_value_cansleep
     => mdio_device_reset
     => phy_device_register
     => fwnode_mdiobus_phy_device_register
     => fwnode_mdiobus_register_phy
     => __of_mdiobus_register
     => stmmac_mdio_register
     => stmmac_dvr_probe
     => stmmac_pltfr_probe
     => devm_stmmac_pltfr_probe
     => qcom_ethqos_probe
     => platform_probe

    /* Deassert */
       systemd-udevd-283     [002] .....     6.882601: gpio_value: 544 set 1
       systemd-udevd-283     [002] .....     6.886014: 
     => gpiod_set_raw_value_commit
     => gpiod_set_value_nocheck
     => gpiod_set_value_cansleep
     => mdio_device_reset
     => phy_probe
     => really_probe
     => __driver_probe_device
     => driver_probe_device
     => __device_attach_driver
     => bus_for_each_drv
     => __device_attach
     => device_initial_probe
     => bus_probe_device
     => device_add
     => phy_device_register
     => fwnode_mdiobus_phy_device_register
     => fwnode_mdiobus_register_phy
     => __of_mdiobus_register
     => stmmac_mdio_register
     => stmmac_dvr_probe
     => stmmac_pltfr_probe
     => devm_stmmac_pltfr_probe
     => qcom_ethqos_probe
     => platform_probe

    /* Deassert */
      NetworkManager-477     [000] .....     7.023144: gpio_value: 544 set 1
      NetworkManager-477     [000] .....     7.026596: 
     => gpiod_set_raw_value_commit
     => gpiod_set_value_nocheck
     => gpiod_set_value_cansleep
     => mdio_device_reset
     => phy_init_hw
     => phy_attach_direct
     => phylink_fwnode_phy_connect
     => __stmmac_open
     => stmmac_open

There's a lot of paths where the device is getting its reset
asserted and deasserted. Let's track the state and only actually
do the assert/deassert when it changes.

Reported-by: Sagar Cheluvegowda 
Signed-off-by: Andrew Halaney 
Reviewed-by: Andrew Lunn 
Link: https://lore.kernel.org/r/20231127-net-phy-reset-once-v2-1-448e8658779e@redhat.com
Signed-off-by: Jakub Kicinski

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

2022-12-06T11:50:00+00:00

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

net: mdio: introduce a shutdown method to mdio device drivers

2021-09-19T11:08:37+00:00

MDIO-attached devices might have interrupts and other things that might
need quiesced when we kexec into a new kernel. Things are even more
creepy when those interrupt lines are shared, and in that case it is
absolutely mandatory to disable all interrupt sources.

Moreover, MDIO devices might be DSA switches, and DSA needs its own
shutdown method to unlink from the DSA master, which is a new
requirement that appeared after commit 2f1e8ea726e9 ("net: dsa: link
interfaces with the DSA master to get rid of lockdep warnings").

So introduce a ->shutdown method in the MDIO device driver structure.

Signed-off-by: Vladimir Oltean 
Reviewed-by: Andrew Lunn 
Reviewed-by: Florian Fainelli 
Signed-off-by: David S. Miller

net: phy: print the function name by func instead of an fixed string

2021-06-16T19:34:07+00:00

It's better to use __func__ than a fixed string to print a function's
name.

Signed-off-by: Wenpeng Liang 
Signed-off-by: Weihang Li 
Reviewed-by: Andrew Lunn 
Signed-off-by: David S. Miller

net: mdio device: use flexible sleeping in reset function

2020-08-03T22:01:02+00:00

MDIO device reset assert and deassert length was created by
usleep_range() but that does not ensure optimal handling of
all the different values from device tree properties.
By switching to the new flexible sleeping helper function,
fsleep(), the correct delay function is called depending on
delay length, e.g. udelay(), usleep_range() or msleep().

Signed-off-by: Bruno Thomsen 
Reviewed-by: Andrew Lunn 
Reviewed-by: Florian Fainelli 
Signed-off-by: David S. Miller

net: phy: Fixup parameters in kerneldoc

2020-07-07T19:47:10+00:00

Correct the kerneldoc for a few structure and function calls,
as reported by C=1 W=1.

Cc: Alexandru Ardelean 
Reviewed-by: Florian Fainelli 
Signed-off-by: Andrew Lunn 
Signed-off-by: David S. Miller

net: phy: mdio: reset MDIO devices even if probe() is not implemented

2020-06-26T20:40:09+00:00

Similarily to PHY drivers - there's no reason to require probe() to be
implemented in order to call mdio_device_reset(). MDIO devices can have
resets defined without needing to do anything in probe().

Signed-off-by: Bartosz Golaszewski 
Reviewed-by: Andrew Lunn 
Reviewed-by: Florian Fainelli 
Signed-off-by: David S. Miller