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Diffstat (limited to 'net/dsa/dsa2.c')
-rw-r--r--net/dsa/dsa2.c31
1 files changed, 29 insertions, 2 deletions
diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index c66abbed4daf..c6d81f2baf4e 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -614,6 +614,32 @@ static int dsa_port_parse_dsa(struct dsa_port *dp)
return 0;
}
+static enum dsa_tag_protocol dsa_get_tag_protocol(struct dsa_port *dp,
+ struct net_device *master)
+{
+ enum dsa_tag_protocol tag_protocol = DSA_TAG_PROTO_NONE;
+ struct dsa_switch *mds, *ds = dp->ds;
+ unsigned int mdp_upstream;
+ struct dsa_port *mdp;
+
+ /* It is possible to stack DSA switches onto one another when that
+ * happens the switch driver may want to know if its tagging protocol
+ * is going to work in such a configuration.
+ */
+ if (dsa_slave_dev_check(master)) {
+ mdp = dsa_slave_to_port(master);
+ mds = mdp->ds;
+ mdp_upstream = dsa_upstream_port(mds, mdp->index);
+ tag_protocol = mds->ops->get_tag_protocol(mds, mdp_upstream,
+ DSA_TAG_PROTO_NONE);
+ }
+
+ /* If the master device is not itself a DSA slave in a disjoint DSA
+ * tree, then return immediately.
+ */
+ return ds->ops->get_tag_protocol(ds, dp->index, tag_protocol);
+}
+
static int dsa_port_parse_cpu(struct dsa_port *dp, struct net_device *master)
{
struct dsa_switch *ds = dp->ds;
@@ -621,20 +647,21 @@ static int dsa_port_parse_cpu(struct dsa_port *dp, struct net_device *master)
const struct dsa_device_ops *tag_ops;
enum dsa_tag_protocol tag_protocol;
- tag_protocol = ds->ops->get_tag_protocol(ds, dp->index);
+ tag_protocol = dsa_get_tag_protocol(dp, master);
tag_ops = dsa_tag_driver_get(tag_protocol);
if (IS_ERR(tag_ops)) {
if (PTR_ERR(tag_ops) == -ENOPROTOOPT)
return -EPROBE_DEFER;
dev_warn(ds->dev, "No tagger for this switch\n");
+ dp->master = NULL;
return PTR_ERR(tag_ops);
}
+ dp->master = master;
dp->type = DSA_PORT_TYPE_CPU;
dp->filter = tag_ops->filter;
dp->rcv = tag_ops->rcv;
dp->tag_ops = tag_ops;
- dp->master = master;
dp->dst = dst;
return 0;