Re: [PATCH net-next v2 1/7] net: devlink: Add unused port flavour

From: Jiri Pirko <jiri@resnulli.us>
To: Andrew Lunn <andrew@lunn.ch>
Cc: Vladimir Oltean <vladimir.oltean@nxp.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Jakub Kicinski <kuba@kernel.org>,
	David Miller <davem@davemloft.net>,
	netdev <netdev@vger.kernel.org>, Jiri Pirko <jiri@nvidia.com>
Subject: Re: [PATCH net-next v2 1/7] net: devlink: Add unused port flavour
Date: Wed, 30 Sep 2020 08:56:04 +0200	[thread overview]
Message-ID: <20200930065604.GI8264@nanopsycho> (raw)
In-Reply-To: <20200929135700.GG3950513@lunn.ch>

Tue, Sep 29, 2020 at 03:57:00PM CEST, andrew@lunn.ch wrote:
>On Tue, Sep 29, 2020 at 03:07:58PM +0200, Jiri Pirko wrote:
>> Tue, Sep 29, 2020 at 01:03:56PM CEST, vladimir.oltean@nxp.com wrote:
>> >On Mon, Sep 28, 2020 at 06:46:14PM -0700, Florian Fainelli wrote:
>> >> That makes sense to me as it would be confusing to suddenly show unused port
>> >> flavors after this patch series land. Andrew, Vladimir, does that work for
>> >> you as well?
>> >
>> >I have nothing to object against somebody adding a '--all' argument to
>> >devlink port commands.
>> 
>> How "unused" is a "flavour"? It seems to me more like a separate
>> attribute as port of any "flavour" may be potentially "unused". I don't
>> think we should mix these 2.
>
>Hi Jiri
>
>Current flavours are:
>
>enum devlink_port_flavour {
>        DEVLINK_PORT_FLAVOUR_PHYSICAL, /* Any kind of a port physically
>                                        * facing the user.
>                                        */
>        DEVLINK_PORT_FLAVOUR_CPU, /* CPU port */
>        DEVLINK_PORT_FLAVOUR_DSA, /* Distributed switch architecture
>                                   * interconnect port.
>                                   */
>        DEVLINK_PORT_FLAVOUR_PCI_PF, /* Represents eswitch port for
>                                      * the PCI PF. It is an internal
>                                      * port that faces the PCI PF.
>                                      */
>        DEVLINK_PORT_FLAVOUR_PCI_VF, /* Represents eswitch port
>                                      * for the PCI VF. It is an internal
>                                      * port that faces the PCI VF.
>                                      */
>        DEVLINK_PORT_FLAVOUR_VIRTUAL, /* Any virtual port facing the user. */
>};
>
>A port in the DSA world is generally just a port on the switch. It is
>not limited in nature. It can be used as a PHYSICAL, or CPU, or a DSA
>port. We don't consider them as unused PHYISCAL ports, or unused CPU
>ports. They are just unused ports. Which is why i added an UNUSED
>flavour.

I get it. But I as I wrote previously, I wonder if used/unused should
not be another attribute. Then the flavour can be "undefined".

But, why do you want to show "unused" ports? Can the user do something
with them? What is the value in showing them?

>
>Now, it could be this world view is actually just a DSA world
>view. Maybe some ASICs have strict roles for their ports? They are not
>configurable? And then i could see it being an attribute? But that
>messes up the DSA world view :-(
>
>      Andrew