mlxsw: spectrum: qdiscs: Remove qdisc before setting a new one

If a qdisc is being replaced by another qdisc of the same type, it can
simply override over its configuration.
However, if it replaces a qdisc of another type, it needs to be removed
before setting the new qdisc.

Signed-off-by: Nogah Frankel <nogahf@mellanox.com>
Reviewed-by: Yuval Mintz <yuvalm@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c
index c896ee7..273300b 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c
@@ -115,6 +115,13 @@ mlxsw_sp_qdisc_replace(struct mlxsw_sp_port *mlxsw_sp_port, u32 handle,
 {
        int err;
 
+       if (mlxsw_sp_qdisc->ops && mlxsw_sp_qdisc->ops->type != ops->type)
+               /* In case this location contained a different qdisc of the
+                * same type we can override the old qdisc configuration.
+                * Otherwise, we need to remove the old qdisc before setting the
+                * new one.
+                */
+               mlxsw_sp_qdisc_destroy(mlxsw_sp_port, mlxsw_sp_qdisc);
        err = ops->check_params(mlxsw_sp_port, mlxsw_sp_qdisc, params);
        if (err)
                goto err_bad_param;