This is a note to let you know that I've just added the patch titled net: dsa: fix preparation of a port STP update to the 4.2-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-dsa-fix-preparation-of-a-port-stp-update.patch and it can be found in the queue-4.2 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Thu Oct 22 17:25:24 PDT 2015 From: Vivien Didelot <vivien.didelot@xxxxxxxxxxxxxxxxxxxx> Date: Tue, 29 Sep 2015 14:17:54 -0400 Subject: net: dsa: fix preparation of a port STP update From: Vivien Didelot <vivien.didelot@xxxxxxxxxxxxxxxxxxxx> [ Upstream commit 57a47532c4312159935c98b7f1cf0e62296b9171 ] 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 <andrew@xxxxxxx> Signed-off-by: Vivien Didelot <vivien.didelot@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/dsa/slave.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) --- a/net/dsa/slave.c +++ b/net/dsa/slave.c @@ -348,12 +348,17 @@ static int dsa_slave_stp_update(struct n 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; Patches currently in stable-queue which might be from vivien.didelot@xxxxxxxxxxxxxxxxxxxx are queue-4.2/net-dsa-fix-preparation-of-a-port-stp-update.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html