Subject: Re: [PATCH v3 net-next 2/4] net: dsa: Link aggregation support

From: Tobias Waldekranz <[email-masked]>
Date: Wed, 02 Dec 2020 22:29:38 +0100

On Wed, Dec 02, 2020 at 10:58, Jakub Kicinski <[email-masked]> wrote:
> On Wed,  2 Dec 2020 10:13:54 +0100 Tobias Waldekranz wrote:
>> Monitor the following events and notify the driver when:
>> 
>> - A DSA port joins/leaves a LAG.
>> - A LAG, made up of DSA ports, joins/leaves a bridge.
>> - A DSA port in a LAG is enabled/disabled (enabled meaning
>>   "distributing" in 802.3ad LACP terms).
>> 
>> Each LAG interface to which a DSA port is attached is represented by a
>> `struct dsa_lag` which is globally reachable from the switch tree and
>> from each associated port.
>> 
>> When a LAG joins a bridge, the DSA subsystem will treat that as each
>> individual port joining the bridge. The driver may look at the port's
>> LAG pointer to see if it is associated with any LAG, if that is
>> required. This is analogue to how switchdev events are replicated out
>> to all lower devices when reaching e.g. a LAG.
>> 
>> Signed-off-by: Tobias Waldekranz <[email-masked]>
>
> Any idea where this is coming from?
>
> net/dsa/slave.c: note: in included file:
> net/dsa/dsa_priv.h:194:31: error: incompatible types in comparison expression (different address spaces):
> net/dsa/dsa_priv.h:194:31:    struct net_device [noderef] __rcu *
> net/dsa/dsa_priv.h:194:31:    struct net_device *

Sorry about this. I missed an rtnl_dereference in the refactor between
v2->v3. I have now integrated sparse into my workflow so at least this
should not happen again.