mlxsw: spectrum: Prevent invalid ingress buffer mapping

Packets entering the switch are mapped to a Switch Priority (SP)
according to their PCP value (untagged frames are mapped to SP 0).

The packets are classified to a priority group (PG) buffer in the port's
headroom according to their SP.

The switch maintains another mapping (SP to IEEE priority), which is
used to generate PFC frames for lossless PGs. This mapping is
initialized to IEEE = SP % 8.

Therefore, when mapping SP 'x' to PG 'y' we create a situation in which
an IEEE priority is mapped to two different PGs:

IEEE 'x' ---> SP 'x' ---> PG 'y'
IEEE 'x' ---> SP 'x + 8' ---> PG '0' (default)

Which is invalid, as a flow can use only one PG buffer.

Fix this by mapping both SP 'x' and 'x + 8' to the same PG buffer.

Fixes: 8e8dfe9fdf06 ("mlxsw: spectrum: Add IEEE 802.1Qaz ETS support")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_buffers.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_buffers.c
index a3720a0fad7d..074cdda7b6f3 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_buffers.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_buffers.c
@@ -194,7 +194,7 @@ static int mlxsw_sp_port_pb_prio_init(struct mlxsw_sp_port *mlxsw_sp_port)
 
 	mlxsw_reg_pptb_pack(pptb_pl, mlxsw_sp_port->local_port);
 	for (i = 0; i < IEEE_8021QAZ_MAX_TCS; i++)
-		mlxsw_reg_pptb_prio_to_buff_set(pptb_pl, i, 0);
+		mlxsw_reg_pptb_prio_to_buff_pack(pptb_pl, i, 0);
 	return mlxsw_reg_write(mlxsw_sp_port->mlxsw_sp->core, MLXSW_REG(pptb),
 			       pptb_pl);
 }