From: Russell King rmk+kernel@armlinux.org.uk
[ Upstream commit 9c2054a5cf415a9dc32c91ffde78399955deb571 ]
When a DSA port is added to a bridge and brought up, the resulting STP state programmed into the hardware depends on the order that these operations are performed. However, the Linux bridge code believes that the port is in disabled mode.
If the DSA port is first added to a bridge and then brought up, it will be in blocking mode. If it is brought up and then added to the bridge, it will be in disabled mode.
This difference is caused by DSA always setting the STP mode in dsa_port_enable() whether or not this port is part of a bridge. Since bridge always sets the STP state when the port is added, brought up or taken down, it is unnecessary for us to manipulate the STP state.
Apparently, this code was copied from Rocker, and the very next day a similar fix for Rocker was merged but was not propagated to DSA. See e47172ab7e41 ("rocker: put port in FORWADING state after leaving bridge")
Fixes: b73adef67765 ("net: dsa: integrate with SWITCHDEV for HW bridging") Signed-off-by: Russell King rmk+kernel@armlinux.org.uk Reviewed-by: Vivien Didelot vivien.didelot@gmail.com Reviewed-by: Florian Fainelli f.fainelli@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/dsa/port.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/net/dsa/port.c b/net/dsa/port.c index ed0595459df1..ea7efc86b9d7 100644 --- a/net/dsa/port.c +++ b/net/dsa/port.c @@ -69,7 +69,6 @@ static void dsa_port_set_state_now(struct dsa_port *dp, u8 state)
int dsa_port_enable(struct dsa_port *dp, struct phy_device *phy) { - u8 stp_state = dp->bridge_dev ? BR_STATE_BLOCKING : BR_STATE_FORWARDING; struct dsa_switch *ds = dp->ds; int port = dp->index; int err; @@ -80,7 +79,8 @@ int dsa_port_enable(struct dsa_port *dp, struct phy_device *phy) return err; }
- dsa_port_set_state_now(dp, stp_state); + if (!dp->bridge_dev) + dsa_port_set_state_now(dp, BR_STATE_FORWARDING);
return 0; } @@ -90,7 +90,8 @@ void dsa_port_disable(struct dsa_port *dp, struct phy_device *phy) struct dsa_switch *ds = dp->ds; int port = dp->index;
- dsa_port_set_state_now(dp, BR_STATE_DISABLED); + if (!dp->bridge_dev) + dsa_port_set_state_now(dp, BR_STATE_DISABLED);
if (ds->ops->port_disable) ds->ops->port_disable(ds, port, phy);