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author | Vladimir Oltean <vladimir.oltean@nxp.com> | 2022-02-07 19:15:51 +0300 |
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committer | Jakub Kicinski <kuba@kernel.org> | 2022-02-09 07:30:35 +0300 |
commit | bd488afc3b39e045ba71aab472233f2a78726e7b (patch) | |
tree | 4d7a004ed70f2ae9659bb9b9d3763e8979f4ddbe | |
parent | 209bdb7ec6a28c7cdf580a0a98afbc9fc3b98932 (diff) | |
download | linux-bd488afc3b39e045ba71aab472233f2a78726e7b.tar.xz |
net: dsa: seville: register the mdiobus under devres
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 Seville VSC9959 switch is a platform 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 seville 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 seville driver has a code structure that could accommodate both the
mdiobus_unregister and mdiobus_free calls, but it has an external
dependency upon mscc_miim_setup() from mdio-mscc-miim.c, which calls
devm_mdiobus_alloc_size() on its behalf. So rather than restructuring
that, and exporting yet one more symbol mscc_miim_teardown(), let's work
with devres and replace of_mdiobus_register with the devres variant.
When we use all-devres, we can ensure that devres doesn't free a
still-registered bus (it either runs both callbacks, or none).
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>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-rw-r--r-- | drivers/net/dsa/ocelot/seville_vsc9953.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/net/dsa/ocelot/seville_vsc9953.c b/drivers/net/dsa/ocelot/seville_vsc9953.c index 8c1c9da61602..f2f1608a476c 100644 --- a/drivers/net/dsa/ocelot/seville_vsc9953.c +++ b/drivers/net/dsa/ocelot/seville_vsc9953.c @@ -1029,7 +1029,7 @@ static int vsc9953_mdio_bus_alloc(struct ocelot *ocelot) } /* Needed in order to initialize the bus mutex lock */ - rc = of_mdiobus_register(bus, NULL); + rc = devm_of_mdiobus_register(dev, bus, NULL); if (rc < 0) { dev_err(dev, "failed to register MDIO bus\n"); return rc; @@ -1083,7 +1083,8 @@ static void vsc9953_mdio_bus_free(struct ocelot *ocelot) mdio_device_free(mdio_device); lynx_pcs_destroy(phylink_pcs); } - mdiobus_unregister(felix->imdio); + + /* mdiobus_unregister and mdiobus_free handled by devres */ } static const struct felix_info seville_info_vsc9953 = { |