[PATCH 4.4 282/312] net: dsa: mv88e6xxx: enable SA learning on DSA ports

From: Greg Kroah-Hartman
Date: Fri May 08 2020 - 09:13:30 EST


From: Vivien Didelot <vivien.didelot@xxxxxxxxxxxxxxxxxxxx>

commit 996ecb8246676100af2a4dc1cfed747712a3c85f upstream.

In multi-chip systems, DSA Tag ports must learn SA addresses in order to
correctly switch frames between interconnected chips.

This fixes cross-chip hardware bridging in a VLAN filtering aware
system, because a bridge group gets implemented as an hardware 802.1Q
VLAN and thus DSA and user ports share the same FDB.

Fixes: 4c7ea3c0791e ("net: dsa: mv88e6xxx: disable SA learning for DSA and CPU ports")
Signed-off-by: Vivien Didelot <vivien.didelot@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/net/dsa/mv88e6xxx.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/net/dsa/mv88e6xxx.c
+++ b/drivers/net/dsa/mv88e6xxx.c
@@ -2064,8 +2064,8 @@ static int mv88e6xxx_setup_port(struct d
* the other bits clear.
*/
reg = 1 << port;
- /* Disable learning for DSA and CPU ports */
- if (dsa_is_cpu_port(ds, port) || dsa_is_dsa_port(ds, port))
+ /* Disable learning for CPU port */
+ if (dsa_is_cpu_port(ds, port))
reg = 0;

ret = _mv88e6xxx_reg_write(ds, REG_PORT(port), PORT_ASSOC_VECTOR, reg);