From: Vladimir Oltean <olteanv@gmail.com>
To: Andrew Lunn <andrew@lunn.ch>
Cc: Tobias Waldekranz <tobias@waldekranz.com>,
davem@davemloft.net, kuba@kernel.org, vivien.didelot@gmail.com,
f.fainelli@gmail.com, netdev@vger.kernel.org, robh+dt@kernel.org,
devicetree@vger.kernel.org
Subject: Re: [PATCH net-next 2/3] net: dsa: Allow default tag protocol to be overridden from DT
Date: Mon, 29 Mar 2021 10:15:59 +0300 [thread overview]
Message-ID: <20210329071559.nmg56nxft5vim5r7@skbuf> (raw)
In-Reply-To: <YGD9d/zeJtAXxC8K@lunn.ch>
On Mon, Mar 29, 2021 at 12:04:39AM +0200, Andrew Lunn wrote:
> On Mon, Mar 29, 2021 at 12:53:09AM +0300, Vladimir Oltean wrote:
> > On Sun, Mar 28, 2021 at 05:52:43PM +0200, Andrew Lunn wrote:
> > > > +static int dsa_switch_setup_tag_protocol(struct dsa_switch *ds)
> > > > +{
> > > > + const struct dsa_device_ops *tag_ops = ds->dst->tag_ops;
> > > > + struct dsa_switch_tree *dst = ds->dst;
> > > > + int port, err;
> > > > +
> > > > + if (tag_ops->proto == dst->default_proto)
> > > > + return 0;
> > > > +
> > > > + if (!ds->ops->change_tag_protocol) {
> > > > + dev_err(ds->dev, "Tag protocol cannot be modified\n");
> > > > + return -EINVAL;
> > > > + }
> > > > +
> > > > + for (port = 0; port < ds->num_ports; port++) {
> > > > + if (!(dsa_is_dsa_port(ds, port) || dsa_is_cpu_port(ds, port)))
> > > > + continue;
> > >
> > > dsa_is_dsa_port() is interesting. Do we care about the tagging
> > > protocol on DSA ports? We never see that traffic?
> >
> > I believe this comes from me (see dsa_switch_tag_proto_match). I did not
> > take into consideration at that time the fact that Marvell switches can
> > translate between DSA and EDSA. So I assumed that every switch in the
> > tree needs a notification about the tagging protocol, not just the
> > top-most one.
>
> Hi Vladimir
>
> static int mv88e6xxx_setup_port_mode(struct mv88e6xxx_chip *chip, int port)
> {
> if (dsa_is_dsa_port(chip->ds, port))
> return mv88e6xxx_set_port_mode_dsa(chip, port);
>
> So DSA ports, the ports connecting two switches together, are hard
> coded to use DSA.
>
> if (dsa_is_user_port(chip->ds, port))
> return mv88e6xxx_set_port_mode_normal(chip, port);
>
> /* Setup CPU port mode depending on its supported tag format */
> if (chip->info->tag_protocol == DSA_TAG_PROTO_DSA)
> return mv88e6xxx_set_port_mode_dsa(chip, port);
>
> if (chip->info->tag_protocol == DSA_TAG_PROTO_EDSA)
> return mv88e6xxx_set_port_mode_edsa(chip, port);
>
> CPU ports can be configured to DSA or EDSA.
>
> The switches seem happy to translate between DSA and EDSA as needed.
I agree, and this is a particular feature of Marvell, not something that
can be said in general. However, I have nothing against deleting the
dsa_is_dsa_port checks from dsa_switch_tag_proto_match and from Tobias'
patch, since nobody needs them at the moment.
next prev parent reply other threads:[~2021-03-29 7:16 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-26 10:56 [PATCH net-next 0/3] net: dsa: Allow default tag protocol to be overridden from DT Tobias Waldekranz
2021-03-26 10:56 ` [PATCH net-next 1/3] net: dsa: mv88e6xxx: Allow dynamic reconfiguration of tag protocol Tobias Waldekranz
2021-03-28 15:24 ` Andrew Lunn
2021-04-06 9:07 ` Tobias Waldekranz
2021-04-06 13:30 ` Andrew Lunn
2021-03-26 10:56 ` [PATCH net-next 2/3] net: dsa: Allow default tag protocol to be overridden from DT Tobias Waldekranz
2021-03-26 12:57 ` Vladimir Oltean
2021-03-26 13:33 ` Tobias Waldekranz
2021-03-31 13:20 ` Vladimir Oltean
2021-03-28 15:52 ` Andrew Lunn
2021-03-28 21:53 ` Vladimir Oltean
2021-03-28 22:04 ` Andrew Lunn
2021-03-29 7:15 ` Vladimir Oltean [this message]
2021-03-26 10:56 ` [PATCH net-next 3/3] dt-bindings: net: dsa: Document dsa,tag-protocol property Tobias Waldekranz
2021-03-27 18:13 ` Rob Herring
2021-04-06 9:52 ` Tobias Waldekranz
2021-04-06 13:30 ` Andrew Lunn
2021-04-07 23:34 ` Vladimir Oltean
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