Subject: Re: [PATCH v4 net-next 2/5] net: dsa: Don't offload port attributes on standalone ports

From: Tobias Waldekranz <[email-masked]>
Date: Wed, 16 Dec 2020 20:32:51 +0100

On Wed, Dec 16, 2020 at 18:27, Vladimir Oltean <[email-masked]> wrote:
> On Wed, Dec 16, 2020 at 05:00:53PM +0100, Tobias Waldekranz wrote:
>> In a situation where a standalone port is indirectly attached to a
>> bridge (e.g. via a LAG) which is not offloaded, do not offload any
>> port attributes either. The port should behave as a standard NIC.
>> 
>> Previously, on mv88e6xxx, this meant that in the following setup:
>> 
>>      br0
>>      /
>>   team0
>>    / \
>> swp0 swp1
>> 
>> If vlan filtering was enabled on br0, swp0's and swp1's QMode was set
>> to "secure". This caused all untagged packets to be dropped, as their
>> default VID (0) was not loaded into the VTU.
>> 
>> Signed-off-by: Tobias Waldekranz <[email-masked]>
>> ---
>>  net/dsa/slave.c | 3 +++
>>  1 file changed, 3 insertions(+)
>> 
>> diff --git a/net/dsa/slave.c b/net/dsa/slave.c
>> index 4a0498bf6c65..faae8dcc0849 100644
>> --- a/net/dsa/slave.c
>> +++ b/net/dsa/slave.c
>> @@ -274,6 +274,9 @@ static int dsa_slave_port_attr_set(struct net_device *dev,
>>  	struct dsa_port *dp = dsa_slave_to_port(dev);
>>  	int ret;
>>  
>> +	if (attr->orig_dev != dev)
>> +		return -EOPNOTSUPP;
>> +
>
> Should this not be:
>
> 	if (!dsa_port_offloads_netdev(dp, attr->orig_dev))
> 		return -EOPNOTSUPP;
>
> ?

That function is born in the following patch. So here I just align the
filtering with how switchdev objects were handled before this
series. Then in the next patch, all instances are converted to the exact
statement you suggest.

>>  	switch (attr->id) {
>>  	case SWITCHDEV_ATTR_ID_PORT_STP_STATE:
>>  		ret = dsa_port_set_state(dp, attr->u.stp_state, trans);
>> -- 
>> 2.17.1
>>