From: Vladimir Oltean <olteanv@gmail.com>
To: Oleksij Rempel <o.rempel@pengutronix.de>
Cc: Andrew Lunn <andrew@lunn.ch>,
Florian Fainelli <f.fainelli@gmail.com>,
Vivien Didelot <vivien.didelot@gmail.com>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
kernel@pengutronix.de, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org,
Russell King <linux@armlinux.org.uk>
Subject: Re: [PATCH net-next v1] net: dsa: fix bridge support for drivers without port_bridge_flags callback
Date: Wed, 21 Apr 2021 19:40:09 +0300 [thread overview]
Message-ID: <20210421164009.jylcxlab2evi2gcr@skbuf> (raw)
In-Reply-To: <20210421130540.12522-1-o.rempel@pengutronix.de>
On Wed, Apr 21, 2021 at 03:05:40PM +0200, Oleksij Rempel wrote:
> Starting with patch:
> a8b659e7ff75 ("net: dsa: act as passthrough for bridge port flags")
>
> drivers without "port_bridge_flags" callback will fail to join the bridge.
> Looking at the code, -EOPNOTSUPP seems to be the proper return value,
> which makes at least microchip and atheros switches work again.
>
> Fixes: a8b659e7ff75 ("net: dsa: act as passthrough for bridge port flags")
> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
> ---
> net/dsa/port.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/dsa/port.c b/net/dsa/port.c
> index 01e30264b25b..6379d66a6bb3 100644
> --- a/net/dsa/port.c
> +++ b/net/dsa/port.c
> @@ -550,7 +550,7 @@ int dsa_port_bridge_flags(const struct dsa_port *dp,
> struct dsa_switch *ds = dp->ds;
>
> if (!ds->ops->port_bridge_flags)
> - return -EINVAL;
> + return -EOPNOTSUPP;
>
> return ds->ops->port_bridge_flags(ds, dp->index, flags, extack);
> }
> --
> 2.29.2
>
The Fixes: tag should be:
Fixes: 5961d6a12c13 ("net: dsa: inherit the actual bridge port flags at join time")
What we return to the bridge is -EINVAL, via dsa_port_pre_bridge_flags()
(it is a two-step calling convention thing). But dsa_port_bridge_flags()
should never return that -EINVAL to the bridge, because the bridge
should just stop if the "pre" call returned an error.
So the -EINVAL return value from dsa_port_bridge_flags() is just for
callers who don't bother to call "pre".
To be honest I don't know why I wrote dsa_port_inherit_brport_flags this
way. It might be better to just do:
-----------------------------[cut here]-----------------------------
diff --git a/net/dsa/port.c b/net/dsa/port.c
index 01e30264b25b..d5e227a77fbc 100644
--- a/net/dsa/port.c
+++ b/net/dsa/port.c
@@ -138,8 +138,12 @@ static int dsa_port_inherit_brport_flags(struct dsa_port *dp,
if (br_port_flag_is_set(brport_dev, BIT(flag)))
flags.val = BIT(flag);
+ err = dsa_port_pre_bridge_flags(dp, flags, extack);
+ if (err == -EINVAL)
+ continue;
+
err = dsa_port_bridge_flags(dp, flags, extack);
- if (err && err != -EOPNOTSUPP)
+ if (err)
return err;
}
@@ -159,8 +163,12 @@ static void dsa_port_clear_brport_flags(struct dsa_port *dp)
flags.mask = BIT(flag);
flags.val = val & BIT(flag);
+ err = dsa_port_pre_bridge_flags(dp, flags, NULL);
+ if (err == -EINVAL)
+ continue;
+
err = dsa_port_bridge_flags(dp, flags, NULL);
- if (err && err != -EOPNOTSUPP)
+ if (err)
dev_err(dp->ds->dev,
"failed to clear bridge port flag %lu: %pe\n",
flags.val, ERR_PTR(err));
-----------------------------[cut here]-----------------------------
next prev parent reply other threads:[~2021-04-21 16:41 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-21 13:05 [PATCH net-next v1] net: dsa: fix bridge support for drivers without port_bridge_flags callback Oleksij Rempel
2021-04-21 16:32 ` Florian Fainelli
2021-04-21 16:40 ` Vladimir Oltean [this message]
2021-04-21 17:50 ` patchwork-bot+netdevbpf
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