[net-next,2/2] net: dsa: rzn1-a5psw: disable learning for standalone ports

Commit Message

Clément Léger March 30, 2023, 8:34 a.m. UTC

When port are in standalone mode, they should have learning disabled to
avoid adding new entries in the MAC lookup table which might be used by
other bridge ports to forward packets. While adding that, also make sure
learning is enabled for CPU port.

Signed-off-by: Clément Léger <[e-mail]>
---
 drivers/net/dsa/rzn1_a5psw.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

Comments

Vladimir Oltean March 30, 2023, 3:20 p.m. UTC | #1

On Thu, Mar 30, 2023 at 10:34:08AM +0200, Clément Léger wrote:
> When port are in standalone mode, they should have learning disabled to
> avoid adding new entries in the MAC lookup table which might be used by
> other bridge ports to forward packets. While adding that, also make sure
> learning is enabled for CPU port.
> 
> Signed-off-by: Clément Léger <[e-mail]>
> ---

Usually I prefer this kind of change to be treated as a bug and
backported to older trees, because we see reports of setups which don't
work due to it. For example, see commit 15f7cfae912e ("net: dsa:
microchip: make learning configurable and keep it off while standalone")
which has a Fixes: tag.

Patch

diff --git a/drivers/net/dsa/rzn1_a5psw.c b/drivers/net/dsa/rzn1_a5psw.c
index bbc1424ed416..3e5062ab0928 100644
--- a/drivers/net/dsa/rzn1_a5psw.c
+++ b/drivers/net/dsa/rzn1_a5psw.c
@@ -336,6 +336,14 @@  static void a5psw_flooding_set_resolution(struct a5psw *a5psw, int port,
 		a5psw_reg_writel(a5psw, offsets[i], a5psw->bridged_ports);
 }
 
+static void a5psw_port_set_standalone(struct a5psw *a5psw, int port,
+				      bool standalone)
+{
+	a5psw_port_learning_set(a5psw, port, !standalone, false);
+	a5psw_flooding_set_resolution(a5psw, port, !standalone);
+	a5psw_port_mgmtfwd_set(a5psw, port, standalone);
+}
+
 static int a5psw_port_bridge_join(struct dsa_switch *ds, int port,
 				  struct dsa_bridge bridge,
 				  bool *tx_fwd_offload,
@@ -351,8 +359,7 @@  static int a5psw_port_bridge_join(struct dsa_switch *ds, int port,
 	}
 
 	a5psw->br_dev = bridge.dev;
-	a5psw_flooding_set_resolution(a5psw, port, true);
-	a5psw_port_mgmtfwd_set(a5psw, port, false);
+	a5psw_port_set_standalone(a5psw, port, false);
 
 	return 0;
 }
@@ -362,8 +369,7 @@  static void a5psw_port_bridge_leave(struct dsa_switch *ds, int port,
 {
 	struct a5psw *a5psw = ds->priv;
 
-	a5psw_flooding_set_resolution(a5psw, port, false);
-	a5psw_port_mgmtfwd_set(a5psw, port, true);
+	a5psw_port_set_standalone(a5psw, port, true);
 
 	/* No more ports bridged */
 	if (a5psw->bridged_ports == BIT(A5PSW_CPU_PORT))
@@ -755,13 +761,15 @@  static int a5psw_setup(struct dsa_switch *ds)
 		if (dsa_port_is_unused(dp))
 			continue;
 
-		/* Enable egress flooding for CPU port */
-		if (dsa_port_is_cpu(dp))
+		/* Enable egress flooding and learning for CPU port */
+		if (dsa_port_is_cpu(dp)) {
 			a5psw_flooding_set_resolution(a5psw, port, true);
+			a5psw_port_learning_set(a5psw, port, true, false);
+		}
 
-		/* Enable management forward only for user ports */
+		/* Enable standalone mode for user ports */
 		if (dsa_port_is_user(dp))
-			a5psw_port_mgmtfwd_set(a5psw, port, true);
+			a5psw_port_set_standalone(a5psw, port, true);
 	}
 
 	return 0;