diff options
Diffstat (limited to 'drivers/net/dsa/sja1105/sja1105_main.c')
| -rw-r--r-- | drivers/net/dsa/sja1105/sja1105_main.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/drivers/net/dsa/sja1105/sja1105_main.c b/drivers/net/dsa/sja1105/sja1105_main.c index fffcaef6b148..b3b5ae3ef408 100644 --- a/drivers/net/dsa/sja1105/sja1105_main.c +++ b/drivers/net/dsa/sja1105/sja1105_main.c @@ -474,7 +474,9 @@ static int sja1105_init_l2_forwarding(struct sja1105_private *priv) { struct sja1105_l2_forwarding_entry *l2fwd; struct dsa_switch *ds = priv->ds; + struct dsa_switch_tree *dst; struct sja1105_table *table; + struct dsa_link *dl; int port, tc; int from, to; @@ -547,6 +549,33 @@ static int sja1105_init_l2_forwarding(struct sja1105_private *priv) } } + /* In odd topologies ("H" connections where there is a DSA link to + * another switch which also has its own CPU port), TX packets can loop + * back into the system (they are flooded from CPU port 1 to the DSA + * link, and from there to CPU port 2). Prevent this from happening by + * cutting RX from DSA links towards our CPU port, if the remote switch + * has its own CPU port and therefore doesn't need ours for network + * stack termination. + */ + dst = ds->dst; + + list_for_each_entry(dl, &dst->rtable, list) { + if (dl->dp->ds != ds || dl->link_dp->cpu_dp == dl->dp->cpu_dp) + continue; + + from = dl->dp->index; + to = dsa_upstream_port(ds, from); + + dev_warn(ds->dev, + "H topology detected, cutting RX from DSA link %d to CPU port %d to prevent TX packet loops\n", + from, to); + + sja1105_port_allow_traffic(l2fwd, from, to, false); + + l2fwd[from].bc_domain &= ~BIT(to); + l2fwd[from].fl_domain &= ~BIT(to); + } + /* Finally, manage the egress flooding domain. All ports start up with * flooding enabled, including the CPU port and DSA links. */ |