Subject: Re: [patch net-next RFC 04/12] dsa: set devlink port attrs for dsa ports

From: Jiri Pirko <[email-masked]>
Date: Thu, 17 May 2018 16:02:39 +0200

Fri, Mar 23, 2018 at 06:09:29PM CET, [email-masked] wrote:
>On 03/23/2018 07:49 AM, Jiri Pirko wrote:
>> Fri, Mar 23, 2018 at 02:30:02PM CET, [email-masked] wrote:
>>> On Thu, Mar 22, 2018 at 11:55:14AM +0100, Jiri Pirko wrote:
>>>> From: Jiri Pirko <[email-masked]>
>>>>
>>>> Set the attrs and allow to expose port flavour to user via devlink.
>>>>
>>>> Signed-off-by: Jiri Pirko <[email-masked]>
>>>> ---
>>>>  net/dsa/dsa2.c | 23 +++++++++++++++++++++++
>>>>  1 file changed, 23 insertions(+)
>>>>
>>>> diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
>>>> index adf50fbc4c13..49453690696d 100644
>>>> --- a/net/dsa/dsa2.c
>>>> +++ b/net/dsa/dsa2.c
>>>> @@ -270,7 +270,27 @@ static int dsa_port_setup(struct dsa_port *dp)
>>>>  	case DSA_PORT_TYPE_UNUSED:
>>>>  		break;
>>>>  	case DSA_PORT_TYPE_CPU:
>>>> +		/* dp->index is used now as port_number. However
>>>> +		 * CPU ports should have separate numbering
>>>> +		 * independent from front panel port numbers.
>>>> +		 */
>>>> +		devlink_port_attrs_set(&dp->devlink_port,
>>>> +				       DEVLINK_PORT_FLAVOUR_CPU,
>>>> +				       dp->index, false, 0);
>>>> +		err = dsa_port_link_register_of(dp);
>>>> +		if (err) {
>>>> +			dev_err(ds->dev, "failed to setup link for port %d.%d\n",
>>>> +				ds->index, dp->index);
>>>> +			return err;
>>>> +		}
>>>
>>> Ah, i get it. These used to be two case statements with one code
>>> block. But you split them apart, so needed to duplicate the
>>> dsa_port_link_register.
>>>
>>> Unfortunately, you forgot to add a 'break;', so it still falls
>>> through, and overwrites the port flavour to DSA.
>> 
>> ah, crap. Don't have hw to test this :/
>> Will fix. Thanks!
>
>You don't need hardware, there is drivers/net/dsa/dsa_loop.c which will
>emulate a DSA switch. It won't create interconnect ports, since only one

Hmm, trying to use dsa_loop. Doing:
modprobe dsa_loop
modprobe fixed_phy

I don't see the netdevs. Any idea what am I doing wrong? Thanks!

>switch can be created with the method chosen, but this would have helped
>you catch the missing break since the "CPU" port would have been
>displayed as "DSA" anyway.
>
>If you need hardware, I am sure this can be somehow arranged. By that, I
>mean something on which you can run upstream Linux on without out of
>tree patches.
>-- 
>Florian