From: Russell King <rmk+ker...@arm.linux.org.uk>
Date: Sun, 24 Jan 2016 09:22:05 +0000
> Since commit 76e398a62712 ("net: dsa: use switchdev obj for VLAN add/del
> ops"), the Marvell 88E6xxx switch has been unable to pass traffic
> between ports - any received traffic is discarded by the switch.
> Taking a port out of bridge mode and configuring a vlan on it also the
> port to start passing traffic.
>
> With the debugfs files re-instated to allow debug of this issue by
> comparing the register settings between the working and non-working
> case, the reason becomes clear:
>
> GLOBAL GLOBAL2 SERDES 0 1 2 3 4 5 6
> - 7: 1111 707f 2001 2 2 2 2 2 0 2
> + 7: 1111 707f 2001 1 1 1 1 1 0 1
>
> Register 7 for the ports is the default vlan tag register, and in the
> non-working setup, it has been set to 2, despite vlan 2 not being
> configured. This causes the switch to drop all packets coming in to
> these ports. The working setup has the default vlan tag register set
> to 1, which is the default vlan when none is configured.
>
> Inspection of the code reveals why. The code prior to this commit
> was:
>
> - for (vid = vlan->vid_begin; vid <= vlan->vid_end; ++vid) {
> ...
> - if (!err && vlan->flags & BRIDGE_VLAN_INFO_PVID)
> - err = ds->drv->port_pvid_set(ds, p->port, vid);
>
> but the new code is:
>
> + for (vid = vlan->vid_begin; vid <= vlan->vid_end; ++vid) {
> ...
> + }
> ...
> + if (pvid)
> + err = _mv88e6xxx_port_pvid_set(ds, port, vid);
>
> This causes the new code to always set the default vlan to one higher
> than the old code.
>
> Fix this.
>
> Fixes: 76e398a62712 ("net: dsa: use switchdev obj for VLAN add/del ops")
> Cc: <sta...@vger.kernel.org>
> Signed-off-by: Russell King <rmk+ker...@arm.linux.org.uk>
Applied and queued up for -stable, thanks Russell.
