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authorVladimir Oltean <vladimir.oltean@nxp.com>2022-02-07 17:15:49 +0100
committerJakub Kicinski <kuba@kernel.org>2022-02-09 05:30:34 +0100
commit08f1a20822349004bb9cc1b153ecb516e9f2889d (patch)
tree9958b4632ccb75e5a39f2e93a45e104f7a8cc62b /drivers
parentnet: dsa: ar9331: register the mdiobus under devres (diff)
downloadlinux-08f1a20822349004bb9cc1b153ecb516e9f2889d.tar.xz
linux-08f1a20822349004bb9cc1b153ecb516e9f2889d.zip
net: dsa: bcm_sf2: don't use devres for mdiobus
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 Starfighter 2 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 bcm_sf2 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 bcm_sf2 driver has the code structure in place for orderly mdiobus removal, so just replace devm_mdiobus_alloc() with the non-devres variant, and add manual free where necessary, to ensure that we don't let devres 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> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/dsa/bcm_sf2.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/net/dsa/bcm_sf2.c b/drivers/net/dsa/bcm_sf2.c
index 33499fcd8848..6afb5db8244c 100644
--- a/drivers/net/dsa/bcm_sf2.c
+++ b/drivers/net/dsa/bcm_sf2.c
@@ -621,7 +621,7 @@ static int bcm_sf2_mdio_register(struct dsa_switch *ds)
get_device(&priv->master_mii_bus->dev);
priv->master_mii_dn = dn;
- priv->slave_mii_bus = devm_mdiobus_alloc(ds->dev);
+ priv->slave_mii_bus = mdiobus_alloc();
if (!priv->slave_mii_bus) {
of_node_put(dn);
return -ENOMEM;
@@ -681,8 +681,10 @@ static int bcm_sf2_mdio_register(struct dsa_switch *ds)
}
err = mdiobus_register(priv->slave_mii_bus);
- if (err && dn)
+ if (err && dn) {
+ mdiobus_free(priv->slave_mii_bus);
of_node_put(dn);
+ }
return err;
}
@@ -690,6 +692,7 @@ static int bcm_sf2_mdio_register(struct dsa_switch *ds)
static void bcm_sf2_mdio_unregister(struct bcm_sf2_priv *priv)
{
mdiobus_unregister(priv->slave_mii_bus);
+ mdiobus_free(priv->slave_mii_bus);
of_node_put(priv->master_mii_dn);
}