From 57a47532c4312159935c98b7f1cf0e62296b9171 Mon Sep 17 00:00:00 2001 From: Vivien Didelot Date: Tue, 29 Sep 2015 14:17:54 -0400 Subject: [PATCH] net: dsa: fix preparation of a port STP update Because of the default 0 value of ret in dsa_slave_port_attr_set, a driver may return -EOPNOTSUPP from the commit phase of a STP state, which triggers a WARN() from switchdev. This happened on a 6185 switch which does not support hardware bridging. Fixes: 3563606258cf ("switchdev: convert STP update to switchdev attr set") Reported-by: Andrew Lunn Signed-off-by: Vivien Didelot Signed-off-by: David S. Miller --- net/dsa/slave.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/net/dsa/slave.c b/net/dsa/slave.c index cce97385f743..7d91f4612ac0 100644 --- a/net/dsa/slave.c +++ b/net/dsa/slave.c @@ -458,12 +458,17 @@ static int dsa_slave_stp_update(struct net_device *dev, u8 state) static int dsa_slave_port_attr_set(struct net_device *dev, struct switchdev_attr *attr) { - int ret = 0; + struct dsa_slave_priv *p = netdev_priv(dev); + struct dsa_switch *ds = p->parent; + int ret; switch (attr->id) { case SWITCHDEV_ATTR_PORT_STP_STATE: - if (attr->trans == SWITCHDEV_TRANS_COMMIT) - ret = dsa_slave_stp_update(dev, attr->u.stp_state); + if (attr->trans == SWITCHDEV_TRANS_PREPARE) + ret = ds->drv->port_stp_update ? 0 : -EOPNOTSUPP; + else + ret = ds->drv->port_stp_update(ds, p->port, + attr->u.stp_state); break; default: ret = -EOPNOTSUPP; -- 2.20.1