Message ID | 20190504135919.23185-2-olteanv@gmail.com |
---|---|
State | Superseded |
Delegated to: | David Miller |
Headers | show |
Series | Traffic support for SJA1105 DSA driver | expand |
On Sat, 4 May 2019 16:59:11 +0300, Vladimir Oltean <olteanv@gmail.com> wrote: > This allows the driver to perform some manipulations of its own during > setup, using generic switchdev calls. Having the notifiers registered at > setup time is important because otherwise any switchdev transaction > emitted during this time would be ignored (dispatched to an empty call > chain). > > One current usage scenario is for the driver to request DSA to set up > 802.1Q based switch tagging for its ports. > > There is no danger for the driver setup code to start racing now with > switchdev events emitted from the network stack (such as bridge core) > even if the notifier is registered earlier. This is because the network > stack needs a net_device as a vehicle to perform switchdev operations, > and the slave net_devices are registered later than the core driver > setup anyway (ds->ops->setup in dsa_switch_setup vs dsa_port_setup). > > Luckily DSA doesn't need a net_device to carry out switchdev callbacks, > and therefore drivers shouldn't assume either that net_devices are > available at the time their switchdev callbacks get invoked. > > Signed-off-by: Vladimir Oltean <olteanv@gmail.com> > Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> > Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Vivien Didelot <vivien.didelot@gmail.com>
diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c index bbc9f56e89b9..f1ad80851616 100644 --- a/net/dsa/dsa2.c +++ b/net/dsa/dsa2.c @@ -371,14 +371,14 @@ static int dsa_switch_setup(struct dsa_switch *ds) if (err) return err; - err = ds->ops->setup(ds); - if (err < 0) - return err; - err = dsa_switch_register_notifier(ds); if (err) return err; + err = ds->ops->setup(ds); + if (err < 0) + return err; + if (!ds->slave_mii_bus && ds->ops->phy_read) { ds->slave_mii_bus = devm_mdiobus_alloc(ds->dev); if (!ds->slave_mii_bus)