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Diffstat (limited to 'Documentation/networking')
| -rw-r--r-- | Documentation/networking/dsa/sja1105.rst | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/Documentation/networking/dsa/sja1105.rst b/Documentation/networking/dsa/sja1105.rst index 7c13b40915c0..ea7bac438cfd 100644 --- a/Documentation/networking/dsa/sja1105.rst +++ b/Documentation/networking/dsa/sja1105.rst @@ -63,6 +63,38 @@ If that changed setting can be transmitted to the switch through the dynamic reconfiguration interface, it is; otherwise the switch is reset and reprogrammed with the updated static configuration. +Traffic support +=============== + +The switches do not support switch tagging in hardware. But they do support +customizing the TPID by which VLAN traffic is identified as such. The switch +driver is leveraging ``CONFIG_NET_DSA_TAG_8021Q`` by requesting that special +VLANs (with a custom TPID of ``ETH_P_EDSA`` instead of ``ETH_P_8021Q``) are +installed on its ports when not in ``vlan_filtering`` mode. This does not +interfere with the reception and transmission of real 802.1Q-tagged traffic, +because the switch does no longer parse those packets as VLAN after the TPID +change. +The TPID is restored when ``vlan_filtering`` is requested by the user through +the bridge layer, and general IP termination becomes no longer possible through +the switch netdevices in this mode. + +The switches have two programmable filters for link-local destination MACs. +These are used to trap BPDUs and PTP traffic to the master netdevice, and are +further used to support STP and 1588 ordinary clock/boundary clock +functionality. + +The following traffic modes are supported over the switch netdevices: + ++--------------------+------------+------------------+------------------+ +| | Standalone | Bridged with | Bridged with | +| | ports | vlan_filtering 0 | vlan_filtering 1 | ++====================+============+==================+==================+ +| Regular traffic | Yes | Yes | No (use master) | ++--------------------+------------+------------------+------------------+ +| Management traffic | Yes | Yes | Yes | +| (BPDU, PTP) | | | | ++--------------------+------------+------------------+------------------+ + Switching features ================== @@ -92,6 +124,28 @@ that VLAN awareness is global at the switch level is that once a bridge with ``vlan_filtering`` enslaves at least one switch port, the other un-bridged ports are no longer available for standalone traffic termination. +Topology and loop detection through STP is supported. + +L2 FDB manipulation (add/delete/dump) is currently possible for the first +generation devices. Aging time of FDB entries, as well as enabling fully static +management (no address learning and no flooding of unknown traffic) is not yet +configurable in the driver. + +A special comment about bridging with other netdevices (illustrated with an +example): + +A board has eth0, eth1, swp0@eth1, swp1@eth1, swp2@eth1, swp3@eth1. +The switch ports (swp0-3) are under br0. +It is desired that eth0 is turned into another switched port that communicates +with swp0-3. + +If br0 has vlan_filtering 0, then eth0 can simply be added to br0 with the +intended results. +If br0 has vlan_filtering 1, then a new br1 interface needs to be created that +enslaves eth0 and eth1 (the DSA master of the switch ports). This is because in +this mode, the switch ports beneath br0 are not capable of regular traffic, and +are only used as a conduit for switchdev operations. + Device Tree bindings and board design ===================================== |
