From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jiri Pirko <jiri@resnulli.us>
Subject: Re: [patch net-next 09/14] rocker: add rtnl ops for port mode
 [gs]etting
Date: Mon, 5 Oct 2015 17:53:20 +0200
Message-ID: <20151005155320.GN2278@nanopsycho.orion>
References: <1443993949-3915-1-git-send-email-jiri@resnulli.us>
 <1443993949-3915-10-git-send-email-jiri@resnulli.us>
 <CAE4R7bA6+_WUQ5BXD54zQK7DM64P3FS5D+TdUc1gcpbjd1+oZw@mail.gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Cc: Netdev <netdev@vger.kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	Ido Schimmel <idosch@mellanox.com>, eladr@mellanox.com,
	Thomas Graf <tgraf@suug.ch>,
	Alexei Starovoitov <ast@plumgrid.com>
To: Scott Feldman <sfeldma@gmail.com>
Return-path: <netdev-owner@vger.kernel.org>
Received: from mail-wi0-f181.google.com ([209.85.212.181]:33531 "EHLO
	mail-wi0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1751540AbbJEPxZ (ORCPT
	<rfc822;netdev@vger.kernel.org>); Mon, 5 Oct 2015 11:53:25 -0400
Received: by wiclk2 with SMTP id lk2so127476492wic.0
        for <netdev@vger.kernel.org>; Mon, 05 Oct 2015 08:53:23 -0700 (PDT)
Content-Disposition: inline
In-Reply-To: <CAE4R7bA6+_WUQ5BXD54zQK7DM64P3FS5D+TdUc1gcpbjd1+oZw@mail.gmail.com>
Sender: netdev-owner@vger.kernel.org
List-ID: <netdev.vger.kernel.org>

Mon, Oct 05, 2015 at 05:41:29PM CEST, sfeldma@gmail.com wrote:
>On Sun, Oct 4, 2015 at 2:25 PM, Jiri Pirko <jiri@resnulli.us> wrote:
>> From: Jiri Pirko <jiri@mellanox.com>
>>
>> Introduce a stub for allowing user to change rocker port world/mode.
>> This is implemented using rtnl changelink op.
>>
>> Signed-off-by: Jiri Pirko <jiri@mellanox.com>
>
>[cut]
>
>> diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
>> index 3a5f263..7da768e 100644
>> --- a/include/uapi/linux/if_link.h
>> +++ b/include/uapi/linux/if_link.h
>> @@ -416,6 +416,17 @@ enum {
>>  };
>>  #define IFLA_GENEVE_MAX        (__IFLA_GENEVE_MAX - 1)
>>
>> +/* Rocker section */
>> +enum {
>> +       IFLA_ROCKER_UNSPEC,
>> +       IFLA_ROCKER_MODE,
>> +       __IFLA_ROCKER_MAX,
>> +};
>> +
>> +#define IFLA_ROCKER_MAX        (__IFLA_ROCKER_MAX - 1)
>> +
>> +#define ROCKER_MODE_MAX 16
>
>Does this mean there is going to be a "ip link set dev DEV type rocker
>mode MODE" command option?
>
>It doesn't seem right to be adding driver-specific IFLA_'s here.  I
>think this sets bad precedence for other drivers to add their own
>knobs without thinking about a generic shared mechanism.

I understand you point. I somehow share it as well. But on the other
hand, That is neat way to set mode of the port, and I cannot find other
this nice.


>
>Actually, I don't see the point of letting the user dynamically change
>the port mode.  I would prefer this knob be moved to qemu/rocker.  Let
>the port mode be specified on device creation.

Hmm, interesting, why? I find it great for user to be able to switch the
port mode easily on the running system. It is a setting of a port.
I don't see why this should be a hard-coded hw setting. We just have
to find a way to expose this to user.


>
>-scott