net: dsa: ar9331: register the mdiobus under devres
stable inclusion from stable-v5.10.101 commit 475ce5dcf2d88fd4f3c213a0ac944e3e40702970 bugzilla: https://gitee.com/openeuler/kernel/issues/I5669Z Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=475ce5dcf2d88fd4f3c213a0ac944e3e40702970 -------------------------------- [ Upstream commit 50facd86 ] As explained in commits: 74b6d7d1 ("net: dsa: realtek: register the MDIO bus under devres") 5135e96a ("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: ac3a68d5 ("net: phy: don't abuse devres in devm_mdiobus_register()") Signed-off-by:Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by:
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