| Message ID | 20200404213517.12783-1-f.fainelli@gmail.com |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net] net: dsa: bcm_sf2: Do not register slave MDIO bus with OF | expand |
On Sat, 4 Apr 2020 14:35:17 -0700, Florian Fainelli <f.fainelli@gmail.com> wrote: > We were registering our slave MDIO bus with OF and doing so with > assigning the newly created slave_mii_bus of_node to the master MDIO bus > controller node. This is a bad thing to do for a number of reasons: > > - we are completely lying about the slave MII bus is arranged and yet we > still want to control which MDIO devices it probes. It was attempted > before to play tricks with the bus_mask to perform that: > https://www.spinics.net/lists/netdev/msg429420.html but the approach > was rightfully rejected > > - the device_node reference counting is messed up and we are effectively > doing a double probe on the devices we already probed using the > master, this messes up all resources reference counts (such as clocks) > > The proper fix for this as indicated by David in his reply to the > thread above is to use a platform data style registration so as to > control exactly which devices we probe: > https://www.spinics.net/lists/netdev/msg430083.html > > By using mdiobus_register(), our slave_mii_bus->phy_mask value is used > as intended, and all the PHY addresses that must be redirected towards > our slave MDIO bus is happening while other addresses get redirected > towards the master MDIO bus. > > Fixes: 461cd1b03e32 ("net: dsa: bcm_sf2: Register our slave MDIO bus") > Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Vivien Didelot <vivien.didelot@gmail.com>
From: Florian Fainelli <f.fainelli@gmail.com> Date: Sat, 4 Apr 2020 14:35:17 -0700 > We were registering our slave MDIO bus with OF and doing so with > assigning the newly created slave_mii_bus of_node to the master MDIO bus > controller node. This is a bad thing to do for a number of reasons: > > - we are completely lying about the slave MII bus is arranged and yet we > still want to control which MDIO devices it probes. It was attempted > before to play tricks with the bus_mask to perform that: > https://www.spinics.net/lists/netdev/msg429420.html but the approach > was rightfully rejected > > - the device_node reference counting is messed up and we are effectively > doing a double probe on the devices we already probed using the > master, this messes up all resources reference counts (such as clocks) > > The proper fix for this as indicated by David in his reply to the > thread above is to use a platform data style registration so as to > control exactly which devices we probe: > https://www.spinics.net/lists/netdev/msg430083.html > > By using mdiobus_register(), our slave_mii_bus->phy_mask value is used > as intended, and all the PHY addresses that must be redirected towards > our slave MDIO bus is happening while other addresses get redirected > towards the master MDIO bus. > > Fixes: 461cd1b03e32 ("net: dsa: bcm_sf2: Register our slave MDIO bus") > Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Applied and queued up for -stable.
diff --git a/drivers/net/dsa/bcm_sf2.c b/drivers/net/dsa/bcm_sf2.c index affa5c6e135c..cc95adc5ab4b 100644 --- a/drivers/net/dsa/bcm_sf2.c +++ b/drivers/net/dsa/bcm_sf2.c @@ -480,7 +480,7 @@ static int bcm_sf2_mdio_register(struct dsa_switch *ds) priv->slave_mii_bus->parent = ds->dev->parent; priv->slave_mii_bus->phy_mask = ~priv->indir_phy_mask; - err = of_mdiobus_register(priv->slave_mii_bus, dn); + err = mdiobus_register(priv->slave_mii_bus); if (err && dn) of_node_put(dn);
We were registering our slave MDIO bus with OF and doing so with assigning the newly created slave_mii_bus of_node to the master MDIO bus controller node. This is a bad thing to do for a number of reasons: - we are completely lying about the slave MII bus is arranged and yet we still want to control which MDIO devices it probes. It was attempted before to play tricks with the bus_mask to perform that: https://www.spinics.net/lists/netdev/msg429420.html but the approach was rightfully rejected - the device_node reference counting is messed up and we are effectively doing a double probe on the devices we already probed using the master, this messes up all resources reference counts (such as clocks) The proper fix for this as indicated by David in his reply to the thread above is to use a platform data style registration so as to control exactly which devices we probe: https://www.spinics.net/lists/netdev/msg430083.html By using mdiobus_register(), our slave_mii_bus->phy_mask value is used as intended, and all the PHY addresses that must be redirected towards our slave MDIO bus is happening while other addresses get redirected towards the master MDIO bus. Fixes: 461cd1b03e32 ("net: dsa: bcm_sf2: Register our slave MDIO bus") Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> --- drivers/net/dsa/bcm_sf2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)