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authorVladimir Oltean <vladimir.oltean@nxp.com>2022-02-07 19:15:53 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-02-16 14:56:29 +0300
commitb5652bc50dde7b84e93dfb25479b64b817e377c1 (patch)
treef42157b9486409fd188e5b2ca717b70fe980b607 /drivers/net/dsa
parent46b7472323296329881631da63eb456cb292f788 (diff)
downloadlinux-b5652bc50dde7b84e93dfb25479b64b817e377c1.tar.xz
net: dsa: lantiq_gswip: don't use devres for mdiobus
[ Upstream commit 0d120dfb5d67edc5bcd1804e167dba2b30809afd ] 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 GSWIP 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 GSWIP 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 gswip 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/net/dsa')
-rw-r--r--drivers/net/dsa/lantiq_gswip.c14
1 files changed, 11 insertions, 3 deletions
diff --git a/drivers/net/dsa/lantiq_gswip.c b/drivers/net/dsa/lantiq_gswip.c
index dbd4486a173f..503adf03d2fc 100644
--- a/drivers/net/dsa/lantiq_gswip.c
+++ b/drivers/net/dsa/lantiq_gswip.c
@@ -497,8 +497,9 @@ static int gswip_mdio_rd(struct mii_bus *bus, int addr, int reg)
static int gswip_mdio(struct gswip_priv *priv, struct device_node *mdio_np)
{
struct dsa_switch *ds = priv->ds;
+ int err;
- ds->slave_mii_bus = devm_mdiobus_alloc(priv->dev);
+ ds->slave_mii_bus = mdiobus_alloc();
if (!ds->slave_mii_bus)
return -ENOMEM;
@@ -511,7 +512,11 @@ static int gswip_mdio(struct gswip_priv *priv, struct device_node *mdio_np)
ds->slave_mii_bus->parent = priv->dev;
ds->slave_mii_bus->phy_mask = ~ds->phys_mii_mask;
- return of_mdiobus_register(ds->slave_mii_bus, mdio_np);
+ err = of_mdiobus_register(ds->slave_mii_bus, mdio_np);
+ if (err)
+ mdiobus_free(ds->slave_mii_bus);
+
+ return err;
}
static int gswip_pce_table_entry_read(struct gswip_priv *priv,
@@ -2170,8 +2175,10 @@ disable_switch:
gswip_mdio_mask(priv, GSWIP_MDIO_GLOB_ENABLE, 0, GSWIP_MDIO_GLOB);
dsa_unregister_switch(priv->ds);
mdio_bus:
- if (mdio_np)
+ if (mdio_np) {
mdiobus_unregister(priv->ds->slave_mii_bus);
+ mdiobus_free(priv->ds->slave_mii_bus);
+ }
put_mdio_node:
of_node_put(mdio_np);
for (i = 0; i < priv->num_gphy_fw; i++)
@@ -2194,6 +2201,7 @@ static int gswip_remove(struct platform_device *pdev)
if (priv->ds->slave_mii_bus) {
mdiobus_unregister(priv->ds->slave_mii_bus);
+ mdiobus_free(priv->ds->slave_mii_bus);
of_node_put(priv->ds->slave_mii_bus->dev.of_node);
}