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| author | Vladimir Oltean <vladimir.oltean@nxp.com> | 2022-07-16 21:53:43 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-07-18 12:44:37 +0100 |
| commit | 6ba1a4aa5974f8a47e6322cecc965e6357b58d80 (patch) | |
| tree | d8fcdbc28b16970f8ac6c2762ab53a2043f68aef /Documentation | |
| parent | ea7006a7aaee54a8861e0bfd5cf6a8495fb998a7 (diff) | |
| download | lwn-6ba1a4aa5974f8a47e6322cecc965e6357b58d80.tar.gz lwn-6ba1a4aa5974f8a47e6322cecc965e6357b58d80.zip | |
docs: net: dsa: delete misinformation about -EOPNOTSUPP for FDB/MDB/VLAN
Returning -EOPNOTSUPP does *NOT* mean anything special.
port_vlan_add() is actually called from 2 code paths, one is
vlan_vid_add() from 8021q module and the other is
br_switchdev_port_vlan_add() from switchdev.
The bridge has a wrapper __vlan_vid_add() which first tries via
switchdev, then if that returns -EOPNOTSUPP, tries again via the VLAN RX
filters in the 8021q module. But DSA doesn't distinguish between one
call path and the other when calling the driver's port_vlan_add(), so if
the driver returns -EOPNOTSUPP to switchdev, it also returns -EOPNOTSUPP
to the 8021q module. And the latter is a hard error.
port_fdb_add() is called from the deferred dsa_owq only, so obviously
its return code isn't propagated anywhere, and cannot be interpreted in
any way.
The return code from port_mdb_add() is propagated to the bridge, but
again, this doesn't do anything special when -EOPNOTSUPP is returned,
but rather, br_switchdev_mdb_notify() returns void.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/networking/dsa/dsa.rst | 12 |
1 files changed, 3 insertions, 9 deletions
diff --git a/Documentation/networking/dsa/dsa.rst b/Documentation/networking/dsa/dsa.rst index 330a76c2fab6..69ea35e19755 100644 --- a/Documentation/networking/dsa/dsa.rst +++ b/Documentation/networking/dsa/dsa.rst @@ -951,9 +951,7 @@ Bridge VLAN filtering allowed. - ``port_vlan_add``: bridge layer function invoked when a VLAN is configured - (tagged or untagged) for the given switch port. If the operation is not - supported by the hardware, this function should return ``-EOPNOTSUPP`` to - inform the bridge code to fallback to a software implementation. + (tagged or untagged) for the given switch port.. - ``port_vlan_del``: bridge layer function invoked when a VLAN is removed from the given switch port @@ -961,9 +959,7 @@ Bridge VLAN filtering - ``port_fdb_add``: bridge layer function invoked when the bridge wants to install a Forwarding Database entry, the switch hardware should be programmed with the specified address in the specified VLAN Id in the forwarding database - associated with this VLAN ID. If the operation is not supported, this - function should return ``-EOPNOTSUPP`` to inform the bridge code to fallback to - a software implementation. + associated with this VLAN ID. - ``port_fdb_del``: bridge layer function invoked when the bridge wants to remove a Forwarding Database entry, the switch hardware should be programmed to delete @@ -978,9 +974,7 @@ Bridge VLAN filtering the ``bridge fdb show`` command. - ``port_mdb_add``: bridge layer function invoked when the bridge wants to install - a multicast database entry. If the operation is not supported, this function - should return ``-EOPNOTSUPP`` to inform the bridge code to fallback to a - software implementation. The switch hardware should be programmed with the + a multicast database entry. The switch hardware should be programmed with the specified address in the specified VLAN ID in the forwarding database associated with this VLAN ID. |