diff mbox series

[RFC,v2,net-next,15/16] net: dsa: return -EOPNOTSUPP when driver does not implement .port_lag_join

Message ID 20210318231829.3892920-16-olteanv@gmail.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series Better support for sandwiched LAGs with bridge and DSA | expand

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netdev/build_allmodconfig_warn fail Errors and warnings before: 8 this patch: 8
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Commit Message

Vladimir Oltean March 18, 2021, 11:18 p.m. UTC 
From: Vladimir Oltean <vladimir.oltean@nxp.com>

The DSA core has a layered structure, and even though we end up
returning 0 (success) to user space when setting a bonding/team upper
that can't be offloaded, some parts of the framework actually need to
know that we couldn't offload that.

For example, if dsa_switch_lag_join returns 0 as it currently does,
dsa_port_lag_join has no way to tell a successful offload from a
software fallback, and it will call dsa_port_bridge_join afterwards.
Then we'll think we're offloading the bridge master of the LAG, when in
fact we're not even offloading the LAG. In turn, this will make us set
skb->offload_fwd_mark = true, which is incorrect and the bridge doesn't
like it.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
 net/dsa/switch.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Florian Fainelli March 22, 2021, 3:51 p.m. UTC | #1 
On 3/18/2021 4:18 PM, Vladimir Oltean wrote:
> From: Vladimir Oltean <vladimir.oltean@nxp.com>
> 
> The DSA core has a layered structure, and even though we end up
> returning 0 (success) to user space when setting a bonding/team upper
> that can't be offloaded, some parts of the framework actually need to
> know that we couldn't offload that.
> 
> For example, if dsa_switch_lag_join returns 0 as it currently does,
> dsa_port_lag_join has no way to tell a successful offload from a
> software fallback, and it will call dsa_port_bridge_join afterwards.
> Then we'll think we're offloading the bridge master of the LAG, when in
> fact we're not even offloading the LAG. In turn, this will make us set
> skb->offload_fwd_mark = true, which is incorrect and the bridge doesn't
> like it.
> 
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tobias Waldekranz March 22, 2021, 3:58 p.m. UTC | #2 
On Fri, Mar 19, 2021 at 01:18, Vladimir Oltean <olteanv@gmail.com> wrote:
> From: Vladimir Oltean <vladimir.oltean@nxp.com>
>
> The DSA core has a layered structure, and even though we end up
> returning 0 (success) to user space when setting a bonding/team upper
> that can't be offloaded, some parts of the framework actually need to
> know that we couldn't offload that.
>
> For example, if dsa_switch_lag_join returns 0 as it currently does,
> dsa_port_lag_join has no way to tell a successful offload from a
> software fallback, and it will call dsa_port_bridge_join afterwards.
> Then we'll think we're offloading the bridge master of the LAG, when in
> fact we're not even offloading the LAG. In turn, this will make us set
> skb->offload_fwd_mark = true, which is incorrect and the bridge doesn't
> like it.
>
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> ---

Reviewed-by: Tobias Waldekranz <tobias@waldekranz.com>
diff mbox series

Patch

diff --git a/net/dsa/switch.c b/net/dsa/switch.c
index 4b5da89dc27a..162bbb2f5cec 100644
--- a/net/dsa/switch.c
+++ b/net/dsa/switch.c
@@ -213,7 +213,7 @@  static int dsa_switch_lag_join(struct dsa_switch *ds,
 						   info->port, info->lag,
 						   info->info);
 
-	return 0;
+	return -EOPNOTSUPP;
 }
 
 static int dsa_switch_lag_leave(struct dsa_switch *ds,
@@ -226,7 +226,7 @@  static int dsa_switch_lag_leave(struct dsa_switch *ds,
 		return ds->ops->crosschip_lag_leave(ds, info->sw_index,
 						    info->port, info->lag);
 
-	return 0;
+	return -EOPNOTSUPP;
 }
 
 static bool dsa_switch_mdb_match(struct dsa_switch *ds, int port,