linux.git/drivers/net/dsa, branch v6.8-rc2

net: dsa: vsc73xx: Add null pointer check to vsc73xx_gpio_probe

2024-01-17T01:48:27+00:00

devm_kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure.

Fixes: 05bd97fc559d ("net: dsa: Add Vitesse VSC73xx DSA router driver")
Signed-off-by: Kunwu Chan 
Suggested-by: Jakub Kicinski 
Reviewed-by: Simon Horman 
Link: https://lore.kernel.org/r/20240111072018.75971-1-chentao@kylinos.cn
Signed-off-by: Jakub Kicinski

net: dsa: bcm_sf2: drop priv->master_mii_dn

2024-01-05T11:56:36+00:00

There used to be a of_node_put(priv->master_mii_dn) call in
bcm_sf2_mdio_unregister(), which was accidentally deleted in commit
6ca80638b90c ("net: dsa: Use conduit and user terms").

But it's not needed - we don't need to hold a reference on the
"brcm,unimac-mdio" OF node for that long, since we don't do anything
with it. We can release it as soon as we finish bcm_sf2_mdio_register().

Also reduce "if (err && dn)" to just "if (err)". We know "dn", aka the
former priv->master_mii_dn, is non-NULL. Otherwise, of_mdio_find_bus(dn)
would not have been able to find the bus behind "brcm,unimac-mdio".

Signed-off-by: Vladimir Oltean 
Reviewed-by: Alvin Šipraga 
Reviewed-by: Florian Fainelli 
Tested-by: Florian Fainelli 
Reviewed-by: Luiz Angelo Daros de Luca 
Signed-off-by: David S. Miller

net: dsa: bcm_sf2: stop assigning an OF node to the ds->user_mii_bus

2024-01-05T11:56:36+00:00

The bcm_sf2 driver does something strange. Instead of calling
of_mdiobus_register() with an OF node argument, it manually assigns the
bus->dev->of_node and then calls the non-OF mdiobus_register(). This
circumvents some code from __of_mdiobus_register() from running, which
sets the auto-scan mask, parses some device tree properties, etc.

I'm going to go out on a limb and say that the OF node isn't, in fact,
needed at all, and can be removed. The MDIO diversion as initially
implemented in commit 461cd1b03e32 ("net: dsa: bcm_sf2: Register our
slave MDIO bus") looked quite different than it is now, after commit
771089c2a485 ("net: dsa: bcm_sf2: Ensure that MDIO diversion is used").
Initially, it made sense, as bcm_sf2 was registering another set of
driver ops for the "brcm,unimac-mdio" OF node. But now, it deletes all
phandles, which makes "phy-handle"s unable to find PHYs, which means
that it always goes through the OF-unaware dsa_user_phy_connect().

Signed-off-by: Vladimir Oltean 
Reviewed-by: Alvin Šipraga 
Reviewed-by: Florian Fainelli 
Tested-by: Florian Fainelli 
Signed-off-by: David S. Miller

net: dsa: qca8k: use "dev" consistently within qca8k_mdio_register()

2024-01-05T11:56:36+00:00

Accessed either through priv->dev or ds->dev, it is the same device
structure. Keep a single variable which holds a reference to it, and use
it consistently.

Signed-off-by: Vladimir Oltean 
Reviewed-by: Alvin Šipraga 
Reviewed-by: Florian Fainelli 
Reviewed-by: Christian Marangi 
Reviewed-by: Luiz Angelo Daros de Luca 
Signed-off-by: David S. Miller

net: dsa: qca8k: consolidate calls to a single devm_of_mdiobus_register()

2024-01-05T11:56:35+00:00

__of_mdiobus_register() already calls __mdiobus_register() if the
OF node provided as argument is NULL. We can take advantage of that
and simplify the 2 code path, calling devm_of_mdiobus_register() only
once for both cases.

Signed-off-by: Vladimir Oltean 
Reviewed-by: Alvin Šipraga 
Reviewed-by: Florian Fainelli 
Reviewed-by: Christian Marangi 
Reviewed-by: Luiz Angelo Daros de Luca 
Signed-off-by: David S. Miller

net: dsa: qca8k: assign ds->user_mii_bus only for the non-OF case

2024-01-05T11:56:35+00:00

To simplify reasoning about why the DSA framework provides the
ds->user_mii_bus functionality, drivers should only use it if they
need to. The qca8k driver appears to also use it simply as storage
for a pointer, which is not a good enough reason to make the core
much more difficult to follow.

ds->user_mii_bus is useful for only 2 cases:

1. The driver probes on platform_data (no OF)
2. The driver probes on OF, but there is no OF node for the MDIO bus.

It is unclear if case (1) is supported with qca8k. It might not be:
the driver might crash when of_device_get_match_data() returns NULL
and then it dereferences priv->info without NULL checking.

Anyway, let us limit the ds->user_mii_bus usage only to the above cases,
and not assign it when an OF node is present.

The bus->phy_mask assignment follows along with the movement, because
__of_mdiobus_register() overwrites this bus field anyway. The value set
by the driver only matters for the non-OF code path.

Signed-off-by: Vladimir Oltean 
Reviewed-by: Alvin Šipraga 
Reviewed-by: Florian Fainelli 
Reviewed-by: Luiz Angelo Daros de Luca 
Signed-off-by: David S. Miller

net: dsa: qca8k: skip MDIO bus creation if its OF node has status = "disabled"

2024-01-05T11:56:35+00:00

Currently the driver calls the non-OF devm_mdiobus_register() rather
than devm_of_mdiobus_register() for this case, but it seems to rather
be a confusing coincidence, and not a real use case that needs to be
supported.

If the device tree says status = "disabled" for the MDIO bus, we
shouldn't need an MDIO bus at all. Instead, just exit as early as
possible and do not call any MDIO API.

Signed-off-by: Vladimir Oltean 
Reviewed-by: Alvin Šipraga 
Reviewed-by: Florian Fainelli 
Signed-off-by: David S. Miller

net: dsa: qca8k: put MDIO bus OF node on qca8k_mdio_register() failure

2024-01-05T11:56:35+00:00

of_get_child_by_name() gives us an OF node with an elevated refcount,
which should be dropped when we're done with it. This is so that,
if (of_node_check_flag(node, OF_DYNAMIC)) is true, the node's memory can
eventually be freed.

There are 2 distinct paths to be considered in qca8k_mdio_register():

- devm_of_mdiobus_register() succeeds: since commit 3b73a7b8ec38 ("net:
  mdio_bus: add refcounting for fwnodes to mdiobus"), the MDIO core
  treats this well.

- devm_of_mdiobus_register() or anything up to that point fails: it is
  the duty of the qca8k driver to release the OF node.

This change addresses the second case by making sure that the OF node
reference is not leaked.

The "mdio" node may be NULL, but of_node_put(NULL) is safe.

Signed-off-by: Vladimir Oltean 
Reviewed-by: Alvin Šipraga 
Reviewed-by: Florian Fainelli 
Signed-off-by: David S. Miller

net: dsa: lantiq_gswip: ignore MDIO buses disabled in OF

2024-01-05T11:56:35+00:00

If the "lantiq,xrx200-mdio" child has status = "disabled", the MDIO bus
creation should be avoided. Use of_device_is_available() to check for
that, and take advantage of 2 facts:

- of_device_is_available(NULL) returns false
- of_node_put(NULL) is a no-op

Signed-off-by: Vladimir Oltean 
Reviewed-by: Alvin Šipraga 
Reviewed-by: Florian Fainelli 
Signed-off-by: David S. Miller

net: dsa: lantiq_gswip: use devres for internal MDIO bus, not ds->user_mii_bus

2024-01-05T11:56:35+00:00

This driver does not need any of the functionalities that make
ds->user_mii_bus special. Those use cases are listed here:
https://lore.kernel.org/netdev/20231221174746.hylsmr3f7g5byrsi@skbuf/

It just makes use of ds->user_mii_bus only as storage for its own MDIO
bus, which otherwise has no connection to the framework. This is because:

- the gswip driver only probes on OF: it fails if of_device_get_match_data()
  returns NULL

- when the child OF node of the MDIO bus is absent, no MDIO bus is
  registered at all, not even by the DSA framework. In order for that to
  have happened, the gswip driver would have needed to provide
  ->phy_read() and ->phy_write() in struct dsa_switch_ops, which it does
  not.

We can break the connection between the gswip driver and the DSA
framework and still preserve the same functionality.

Since commit 3b73a7b8ec38 ("net: mdio_bus: add refcounting for fwnodes
to mdiobus"), MDIO buses take ownership of the OF node handled to them,
and release it on their own. The gswip driver no longer needs to do
this.

Combine that with devres, and we no longer need to keep track of
anything for teardown purposes.

Signed-off-by: Vladimir Oltean 
Reviewed-by: Alvin Šipraga 
Reviewed-by: Florian Fainelli 
Reviewed-by: Luiz Angelo Daros de Luca 
Signed-off-by: David S. Miller