Re: [PATCH net-next v1] net: dsa: fix bridge support for drivers without port_bridge_flags callback
From: Vladimir Oltean <olteanv@gmail.com>
Date: 2021-04-21 16:41:00
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lkml
Subsystem:
networking [dsa], networking [general], the rest · Maintainers:
Andrew Lunn, Vladimir Oltean, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
On Wed, Apr 21, 2021 at 03:05:40PM +0200, Oleksij Rempel wrote:
quoted hunk ↗ jump to hunk
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]-----------------------------