Re: [PATCH net-next v2 01/10] net: dsa: add debugfs interface

[Egil Hjelmeland <privat@egil-hjelmeland.no>]

On 15. sep. 2017 07:51, Jiri Pirko wrote:
> Thu, Sep 14, 2017 at 11:01:32PM CEST, andrew@lunn.ch wrote:
>>> Can you clarify what type of registers it is you are wanting to read?
>>> We already have ethtool which is meant to allow reading the device
>>> registers for a given netdev. As long as the port has a netdev
>>> associated it then there is no need to be getting into debugfs since
>>> we should probably just be using ethtool.
>>
>> Not all ports of a DSA switch have a netdev. This is by design. The
>> presentation we gave to Netdev 2.1 gives some of the background.
>>
>> Plus a switch has a lot of registers not associated to port. Often a
>> switch has more global registers than port registers.
>>
>>> Also as Jiri pointed out there is already devlink which would probably
>>> be a better way to get the associated information for those pieces
>>> that don't have a netdev associated with them.
>>
>> We have looked at the devlink a few times. The current dpipe code is
>> not generic enough. It makes assumptions about the architecture of the
>> switch, that it is all match/action based. The niche of top of rack
>> switches might be like that, but average switches are not.
>>
>> If dpipe was to support simple generic two dimensional tables, we
>> probably would use it.
>>
>> David suggested making a class device for DSA. It is not ideal, but we
>> are probably going to go that way.
> 
> I believe that is also big mistake.
> 
> Could you put together your requirements so we can work it out to extend
> devlink to support them?
> 
> Thanks.
> 

$ ack -i devlink Documentation/
$ ack -i dpipe Documentation/
$

How you expect new mechanisms to be taken into use with zero documentation?

To all: Why does reviewers nitpick about undocumented formatting rules, 
but not ask about documentation?

Egil