50facd86e9
As explained in commits:
74b6d7d13307 ("net: dsa: realtek: register the MDIO bus under devres")
5135e96a3dd2 ("net: dsa: don't allocate the slave_mii_bus using devres")
mdiobus_free() will panic when called from devm_mdiobus_free() <-
devres_release_all() <- __device_release_driver(), and that mdiobus was
not previously unregistered.
The ar9331 is an MDIO device, so the initial set of constraints that I
thought would cause this (I2C or SPI buses which call ->remove on
->shutdown) do not apply. But there is one more which applies here.
If the DSA master itself is on a bus that calls ->remove from ->shutdown
(like dpaa2-eth, which is on the fsl-mc bus), there is a device link
between the switch and the DSA master, and device_links_unbind_consumers()
will unbind the ar9331 switch driver on shutdown.
So the same treatment must be applied to all DSA switch drivers, which
is: either use devres for both the mdiobus allocation and registration,
or don't use devres at all.
The ar9331 driver doesn't have a complex code structure for mdiobus
removal, so just replace of_mdiobus_register with the devres variant in
order to be all-devres and ensure that we don't free a still-registered
bus.
Fixes: ac3a68d56651 ("net: phy: don't abuse devres in devm_mdiobus_register()")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
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https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.