Device drivers may generally need to keep in sync with bridge's FDB. In particular, for its offload of tc mirror action where the mirrored-to device is a gretap device, mlxsw needs to listen to a number of events. SWITCHDEV_FDB_{ADD,DEL}_TO_DEVICE would be a natural notification to listen to in order to keep up with FDB updates.
However, for removal of FDB entries added due to device activity (as opposed to explicit addition through "bridge fdb add" or similar), there are no notifications. Thus in patch #1, add the "added_by_user" field to switchdev notifications sent for FDB activity. Adapt drivers to ignore activity on non-user-added entries, to maintain the current behavior. Specifically in case of mlxsw, allow mlxsw_sp_span_respin() call for any and all FDB updates. In patch #2, change the bridge driver to actually emit notifications for these FDB entries. Take care not to send notification for bridge updates that itself originate in SWITCHDEV_FDB_*_TO_BRIDGE events. Petr Machata (2): switchdev: Add fdb.added_by_user to switchdev notifications net: bridge: Notify about !added_by_user FDB entries .../ethernet/mellanox/mlxsw/spectrum_switchdev.c | 4 +++ drivers/net/ethernet/rocker/rocker_main.c | 2 ++ include/net/switchdev.h | 1 + net/bridge/br.c | 4 +-- net/bridge/br_fdb.c | 40 +++++++++++++++------- net/bridge/br_private.h | 4 +-- net/bridge/br_switchdev.c | 12 ++++--- net/dsa/slave.c | 5 ++- 8 files changed, 50 insertions(+), 22 deletions(-) -- 2.4.11