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: 3563606258 ("switchdev: convert STP update to switchdev attr set")
Reported-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Vivien Didelot 2015-09-29 14:17:54 -04:00 коммит произвёл David S. Miller
Родитель 9ae6d4935e
Коммит 57a47532c4
1 изменённых файлов: 8 добавлений и 3 удалений

Просмотреть файл

@ -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;