Date:   Tue, 20 Aug 2019 15:09:19 +0300
From:   Vladimir Oltean <olteanv@...il.com>
To:     Florian Fainelli <f.fainelli@...il.com>
Cc:     Vivien Didelot <vivien.didelot@...il.com>,
        Andrew Lunn <andrew@...n.ch>, Ido Schimmel <idosch@...sch.org>,
        Roopa Prabhu <roopa@...ulusnetworks.com>,
        nikolay@...ulusnetworks.com,
        "David S. Miller" <davem@...emloft.net>,
        netdev <netdev@...r.kernel.org>
Subject: Re: [PATCH net-next 4/6] net: dsa: Don't program the VLAN as pvid on
 the upstream port

Hi Florian,

On Tue, 20 Aug 2019 at 06:15, Florian Fainelli <f.fainelli@...il.com> wrote:
>
>
>
> On 8/19/2019 5:00 PM, Vladimir Oltean wrote:
> > Commit b2f81d304cee ("net: dsa: add CPU and DSA ports as VLAN members")
> > programs the VLAN from the bridge into the specified port as well as the
> > upstream port, with the same set of flags.
> >
> > Consider the typical case of installing pvid 1 on user port 1, pvid 2 on
> > user port 2, etc. The upstream port would end up having a pvid equal to
> > the last user port whose pvid was programmed from the bridge. Less than
> > useful.
> >
> > So just don't change the pvid of the upstream port and let it be
> > whatever the driver set it internally to be.
>
> This patch should allow removing the !dsa_is_cpu_port() checks from
> b53_common.c:b53_vlan_add, about time :)
>
> It seems to me that the fundamental issue here is that because we do not
> have a user visible network device that 1:1 maps with the CPU (or DSA)
> ports for that matter (and for valid reasons, they would represent two
> ends of the same pipe), we do not have a good way to control the CPU
> port VLAN attributes.
>
> There was a prior attempt at allowing using the bridge master device to
> program the CPU port's VLAN attributes, see [1], but I did not follow up
> with that until [2] and then life caught me. If you can/want, that would
> be great (not asking for TPS reports).
>
> [1]:
> https://lists.linuxfoundation.org/pipermail/bridge/2016-November/010112.html
> [2]:
> https://lore.kernel.org/lkml/20180624153339.13572-1-f.fainelli@gmail.com/T/
>

So what was the conclusion of that discussion? Should you or should
you not add the check for vlan->flags & BRIDGE_VLAN_INFO_BRENTRY?
I don't exactly handle the meaning of 'master' and 'self' options from
a user perspective.
Right now (no patches applied) I get the following behavior in DSA
(swp2 is already member of br0):

$ echo 1 | sudo tee /sys/class/net/br0/bridge/vlan_filtering
$ sudo bridge vlan add vid 100 dev swp2
$ sudo bridge vlan add vid 101 dev swp2 self
RTNETLINK answers: Operation not supported
$ sudo bridge vlan add vid 102 dev swp2 master
$ sudo bridge vlan add vid 103 dev br0
RTNETLINK answers: Operation not supported
$ sudo bridge vlan add vid 104 dev br0 self
$ sudo bridge vlan add vid 105 dev br0 master
RTNETLINK answers: Operation not supported

$ bridge vlan
port    vlan ids
eth0     1 PVID Egress Untagged

swp5     1 PVID Egress Untagged

swp2     1 PVID Egress Untagged
         100
         102

swp3     1 PVID Egress Untagged

swp4     1 PVID Egress Untagged

br0      1 PVID Egress Untagged
         104

Who returns EOPNOTSUPP for VID 101 and why?
Why is VID 102 not installed in br0? This part I don't understand from
your patchset. Does it mean that the CPU port (br0) will have to be
explicitly configured from now on, even if I run the commands on swp2
with 'master'?


> >
> > Signed-off-by: Vladimir Oltean <olteanv@...il.com>
> > ---
> >  net/dsa/switch.c | 16 ++++++++++++----
> >  1 file changed, 12 insertions(+), 4 deletions(-)
> >
> > diff --git a/net/dsa/switch.c b/net/dsa/switch.c
> > index 84ab2336131e..02ccc53f1926 100644
> > --- a/net/dsa/switch.c
> > +++ b/net/dsa/switch.c
> > @@ -239,17 +239,21 @@ dsa_switch_vlan_prepare_bitmap(struct dsa_switch *ds,
> >                              const struct switchdev_obj_port_vlan *vlan,
> >                              const unsigned long *bitmap)
> >  {
> > +     struct switchdev_obj_port_vlan v = *vlan;
> >       int port, err;
> >
> >       if (!ds->ops->port_vlan_prepare || !ds->ops->port_vlan_add)
> >               return -EOPNOTSUPP;
> >
> >       for_each_set_bit(port, bitmap, ds->num_ports) {
> > -             err = dsa_port_vlan_check(ds, port, vlan);
> > +             if (dsa_is_cpu_port(ds, port) || dsa_is_dsa_port(ds, port))
> > +                     v.flags &= ~BRIDGE_VLAN_INFO_PVID;
> > +
> > +             err = dsa_port_vlan_check(ds, port, &v);
> >               if (err)
> >                       return err;
> >
> > -             err = ds->ops->port_vlan_prepare(ds, port, vlan);
> > +             err = ds->ops->port_vlan_prepare(ds, port, &v);
> >               if (err)
> >                       return err;
> >       }
> > @@ -262,10 +266,14 @@ dsa_switch_vlan_add_bitmap(struct dsa_switch *ds,
> >                          const struct switchdev_obj_port_vlan *vlan,
> >                          const unsigned long *bitmap)
> >  {
> > +     struct switchdev_obj_port_vlan v = *vlan;
> >       int port;
> >
> > -     for_each_set_bit(port, bitmap, ds->num_ports)
> > -             ds->ops->port_vlan_add(ds, port, vlan);
> > +     for_each_set_bit(port, bitmap, ds->num_ports) {
> > +             if (dsa_is_cpu_port(ds, port) || dsa_is_dsa_port(ds, port))
> > +                     v.flags &= ~BRIDGE_VLAN_INFO_PVID;
> > +             ds->ops->port_vlan_add(ds, port, &v);
> > +     }
> >  }
> >
> >  static int dsa_switch_vlan_add(struct dsa_switch *ds,
> >
>
> --
> Florian

Regards,
-Vladimir

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