| Message ID | 20210731191023.1329446-2-dqfext@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mt7530 software fallback bridging fix | expand |
On Sun, Aug 01, 2021 at 03:10:19AM +0800, DENG Qingfang wrote: > Consider the following bridge configuration, where bond0 is not > offloaded: > > +-- br0 --+ > / / | \ > / / | \ > / | | bond0 > / | | / \ > swp0 swp1 swp2 swp3 swp4 > . . . > . . . > A B C > > Address learning is enabled on offloaded ports (swp0~2) and the CPU > port, so when client A sends a packet to C, the following will happen: > > 1. The switch learns that client A can be reached at swp0. > 2. The switch probably already knows that client C can be reached at the > CPU port, so it forwards the packet to the CPU. > 3. The bridge core knows client C can be reached at bond0, so it > forwards the packet back to the switch. > 4. The switch learns that client A can be reached at the CPU port. > 5. The switch forwards the packet to either swp3 or swp4, according to > the packet's tag. > > That makes client A's MAC address flap between swp0 and the CPU port. If > client B sends a packet to A, it is possible that the packet is > forwarded to the CPU. With offload_fwd_mark = 1, the bridge core won't > forward it back to the switch, resulting in packet loss. > > As we have the assisted_learning_on_cpu_port in DSA core now, enable > that and disable hardware learning on the CPU port. > > Signed-off-by: DENG Qingfang <dqfext@gmail.com> > --- Reviewed-by: Vladimir Oltean <oltean@gmail.com>
diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c index 69f21b71614c..7e7e0a35e351 100644 --- a/drivers/net/dsa/mt7530.c +++ b/drivers/net/dsa/mt7530.c @@ -2054,6 +2054,7 @@ mt7530_setup(struct dsa_switch *ds) * as two netdev instances. */ dn = dsa_to_port(ds, MT7530_CPU_PORT)->master->dev.of_node->parent; + ds->assisted_learning_on_cpu_port = true; ds->mtu_enforcement_ingress = true; if (priv->id == ID_MT7530) { @@ -2124,15 +2125,15 @@ mt7530_setup(struct dsa_switch *ds) mt7530_rmw(priv, MT7530_PCR_P(i), PCR_MATRIX_MASK, PCR_MATRIX_CLR); + /* Disable learning by default on all ports */ + mt7530_set(priv, MT7530_PSC_P(i), SA_DIS); + if (dsa_is_cpu_port(ds, i)) { ret = mt753x_cpu_port_enable(ds, i); if (ret) return ret; } else { mt7530_port_disable(ds, i); - - /* Disable learning by default on all user ports */ - mt7530_set(priv, MT7530_PSC_P(i), SA_DIS); } /* Enable consistent egress tag */ mt7530_rmw(priv, MT7530_PVC_P(i), PVC_EG_TAG_MASK, @@ -2289,6 +2290,9 @@ mt7531_setup(struct dsa_switch *ds) mt7530_rmw(priv, MT7530_PCR_P(i), PCR_MATRIX_MASK, PCR_MATRIX_CLR); + /* Disable learning by default on all ports */ + mt7530_set(priv, MT7530_PSC_P(i), SA_DIS); + mt7530_set(priv, MT7531_DBG_CNT(i), MT7531_DIS_CLR); if (dsa_is_cpu_port(ds, i)) { @@ -2297,9 +2301,6 @@ mt7531_setup(struct dsa_switch *ds) return ret; } else { mt7530_port_disable(ds, i); - - /* Disable learning by default on all user ports */ - mt7530_set(priv, MT7530_PSC_P(i), SA_DIS); } /* Enable consistent egress tag */ @@ -2307,6 +2308,7 @@ mt7531_setup(struct dsa_switch *ds) PVC_EG_TAG(MT7530_VLAN_EG_CONSISTENT)); } + ds->assisted_learning_on_cpu_port = true; ds->mtu_enforcement_ingress = true; /* Flush the FDB table */
Consider the following bridge configuration, where bond0 is not offloaded: +-- br0 --+ / / | \ / / | \ / | | bond0 / | | / \ swp0 swp1 swp2 swp3 swp4 . . . . . . A B C Address learning is enabled on offloaded ports (swp0~2) and the CPU port, so when client A sends a packet to C, the following will happen: 1. The switch learns that client A can be reached at swp0. 2. The switch probably already knows that client C can be reached at the CPU port, so it forwards the packet to the CPU. 3. The bridge core knows client C can be reached at bond0, so it forwards the packet back to the switch. 4. The switch learns that client A can be reached at the CPU port. 5. The switch forwards the packet to either swp3 or swp4, according to the packet's tag. That makes client A's MAC address flap between swp0 and the CPU port. If client B sends a packet to A, it is possible that the packet is forwarded to the CPU. With offload_fwd_mark = 1, the bridge core won't forward it back to the switch, resulting in packet loss. As we have the assisted_learning_on_cpu_port in DSA core now, enable that and disable hardware learning on the CPU port. Signed-off-by: DENG Qingfang <dqfext@gmail.com> --- drivers/net/dsa/mt7530.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)