From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Pirko Subject: Re: [PATCH net-next v2] net: dsa: make "label" property optional for dsa2 Date: Wed, 11 Jan 2017 08:26:09 +0100 Message-ID: <20170111072609.GA1852@nanopsycho> References: <20170109073236.GA1862@nanopsycho> <877f6446lp.fsf@weeman.i-did-not-set--mail-host-address--so-tickle-me> <20170109151131.GC1862@nanopsycho> <87y3yk2q5e.fsf@weeman.i-did-not-set--mail-host-address--so-tickle-me> <20170109160632.GD1862@nanopsycho> <89492624-84f2-ca73-75dd-7fa10819ad09@gmail.com> <20170109175842.GH1862@nanopsycho> <3897e83d-83a6-7bb1-311d-ae228390f757@gmail.com> <20170110095524.GA1827@nanopsycho> <3c7e5102-cef7-c909-a192-6238103e444e@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Vivien Didelot , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@savoirfairelinux.com, "David S. Miller" , Andrew Lunn , Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= , Andrey Smirnov To: Florian Fainelli Return-path: Content-Disposition: inline In-Reply-To: <3c7e5102-cef7-c909-a192-6238103e444e@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Tue, Jan 10, 2017 at 06:58:18PM CET, f.fainelli@gmail.com wrote: >On 01/10/2017 01:55 AM, Jiri Pirko wrote: >> Mon, Jan 09, 2017 at 07:06:39PM CET, f.fainelli@gmail.com wrote: >>> On 01/09/2017 09:58 AM, Jiri Pirko wrote: >>>> Mon, Jan 09, 2017 at 06:42:07PM CET, f.fainelli@gmail.com wrote: >>>>> On 01/09/2017 08:06 AM, Jiri Pirko wrote: >>>>>> Mon, Jan 09, 2017 at 04:45:33PM CET, vivien.didelot@savoirfairelinux.com wrote: >>>>>>> Hi Jiri, >>>>>>> >>>>>>> Jiri Pirko writes: >>>>>>> >>>>>>>>> Extra question: shouldn't phys_port_{id,name} be switchdev attributes in >>>>>>>> >>>>>>>> Again, phys_port_id has nothing to do with switches. Should be removed >>>>>>>> from dsa because its use there is incorrect. >>>>>>> >>>>>>> Florian, since 3a543ef just got in, can it be reverted? >>>>>> >>>>>> Yes, please revert it. It is only in net-next. >>>>> >>>>> Maybe the use case can be understood before reverting the change. How do >>>>> we actually the physical port number of an Ethernet switch per-port >>>>> network device? The name is not enough, because there are plenty of >>>>> cases where we need to manipulate a physical port number (be it just for >>>>> informational purposes). >>>> >>>> Like what? >>> >>> Specifying the physical port number (and derive a queue number >>> eventually) for some ethtool (e.g: rxnfc)/tc (queue mapping) operations >>> where there is an action/queue/port destination argument that gets >>> programmed into the hardware. >> >> Could you point me to a real example? User command? > >ethtool --config-nfc moca flow-type udp4 src-ip 192.168.1.20 dst-ip \ > 192.168.1.10 src-port 49884 dst-port 5001 action 2 > >Where 2 here designates a port number, users need to be able to look up >the physical port number corresponding to an interface to know which >value to put in this command. 2 is not a port number but RX queue number. I believe you need to ditinguish that and port_name. Not sure how are they related. > >Yes I know we can do the same thing with cls_flower, possibly by >referencing network devices directly. Yes, that is what you should do. I believe that using config-nfc is not correct for this use-case. > >> >> >>> >>> You already have the originating port number from the interface you call >>> the method against, but you also need the destination port number since >>> that is what the HW understands. >> >> This is internal to kernel? I fail to understand what you mean exactly. > >See the command above, from using the "moca" netdev here, we can access >the DSA private network device (dsa_slave_priv) structure and get the >port number from there, and pass this down to the switch driver. The >switch driver also takes another port number (and eventually a queue >number) to program classification filters. > >> >> >>> >>> Aside from that, it is useful for allowing interface naming in user >>> space if you don't want to use labels. >>> >>>> >>>> Why the name is not enough? This is something propagated to userspace >>>> and never used internally in kernel. >>> >>> Because the name is not reflective of the port number in some switches. >>> In my case for instance, we have 5 ports that are named after the >>> entities they connect to (an integrated Gigabit PHY, two RGMII pads, one >>> MoCA interface, and the CPU) >>> >> >> Again, I'm missing why you need a portnumber as a Integer to userspace. >> From driver, you can expose phys_port_name: > >If we are exposing the port name here, we may as well expose the DSA >"label" instead of the physical port number number? Yeah, that makes sense. > >I don't deny my change may be misusing what phys_port_id was originally >designed for, but providing "p0" instead of "0" to user-space, what >value is there in adding the "p" in front really? It's up to a driver. He knows how the front panel names look like. >-- >Florian