On Wed, 20 Feb 2019 10:32:52 +0000, Russell King <rmk+ker...@armlinux.org.uk>
wrote:
> When a DSA port is added to a bridge and brought up, the resulting STP
> state programmed into the hardware depends on the order that these
> operations are performed. However, the Linux bridge code believes that
> the port is in disabled mode.
>
> If the DSA port is first added to a bridge and then brought up, it will
> be in blocking mode. If it is brought up and then added to the bridge,
> it will be in disabled mode.
>
> This difference is caused by DSA always setting the STP mode in
> dsa_port_enable() whether or not this port is part of a bridge. Since
> bridge always sets the STP state when the port is added, brought up or
> taken down, it is unnecessary for us to manipulate the STP state.
>
> Apparently, this code was copied from Rocker, and the very next day a
> similar fix for Rocker was merged but was not propagated to DSA. See
> e47172ab7e41 ("rocker: put port in FORWADING state after leaving bridge")
>
> Fixes: b73adef67765 ("net: dsa: integrate with SWITCHDEV for HW bridging")
> Signed-off-by: Russell King <rmk+ker...@armlinux.org.uk>
Reviewed-by: Vivien Didelot <vivien.dide...@gmail.com>
