From: Russell King Date: Wed, 20 Feb 2019 10:32:52 +0000 (+0000) Subject: net: dsa: fix unintended change of bridge interface STP state X-Git-Tag: v5.0-rc8~2^2~36 X-Git-Url: http://git.samba.org/samba.git/?p=sfrench%2Fcifs-2.6.git;a=commitdiff_plain;h=9c2054a5cf415a9dc32c91ffde78399955deb571;hp=40e196a906d969fd10d885c692d2674b3d657006 net: dsa: fix unintended change of bridge interface STP state 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 Reviewed-by: Vivien Didelot Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- diff --git a/net/dsa/port.c b/net/dsa/port.c index 2d7e01b23572..2a2a878b5ce3 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);