.. SPDX-License-Identifier: GPL-2.0

=======================
sja1105 devlink support
=======================

This document describes the devlink features implemented
by the ``sja1105`` device driver.

Parameters
==========

.. list-table:: Driver-specific parameters implemented
  :widths: 5 5 5 85

  * - Name
    - Type
    - Mode
    - Description
  * - ``best_effort_vlan_filtering``
    - Boolean
    - runtime
    - Allow plain ETH_P_8021Q headers to be used as DSA tags.

      Benefits:

      - Can terminate untagged traffic over switch net
        devices even when enslaved to a bridge with
        vlan_filtering=1.
      - Can terminate VLAN-tagged traffic over switch net
        devices even when enslaved to a bridge with
        vlan_filtering=1, with some constraints (no more than
        7 non-pvid VLANs per user port).
      - Can do QoS based on VLAN PCP and VLAN membership
        admission control for autonomously forwarded frames
        (regardless of whether they can be terminated on the
        CPU or not).

      Drawbacks:

      - User cannot use VLANs in range 1024-3071. If the
	switch receives frames with such VIDs, it will
	misinterpret them as DSA tags.
      - Switch uses Shared VLAN Learning (FDB lookup uses
	only DMAC as key).
      - When VLANs span cross-chip topologies, the total
	number of permitted VLANs may be less than 7 per
	port, due to a maximum number of 32 VLAN retagging
	rules per switch.