Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756983AbdIHTyI (ORCPT ); Fri, 8 Sep 2017 15:54:08 -0400 Received: from mail-qt0-f196.google.com ([209.85.216.196]:37573 "EHLO mail-qt0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756751AbdIHTyG (ORCPT ); Fri, 8 Sep 2017 15:54:06 -0400 X-Google-Smtp-Source: AOwi7QCOoLDxA2SK4qedfjXFoofAzib/Xd7gR5jq1ubM8+574h7sBDNWVBMqFjOplnk4VJaK6e/s0w== Subject: Re: [PATCH RFC] Update documentation for KSZ DSA drivers so that new drivers can be added To: Tristram.Ha@microchip.com, muvarov@gmail.com Cc: andrew@lunn.ch, pavel@ucw.cz, nathan.leigh.conrad@gmail.com, vivien.didelot@savoirfairelinux.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Woojung.Huh@microchip.com References: <93AF473E2DA327428DE3D46B72B1E9FD41121A5B@CHN-SV-EXMX02.mchp-main.com> <8e4aa981-7f41-047d-2101-370118b4f2c0@gmail.com> <93AF473E2DA327428DE3D46B72B1E9FD41121EF7@CHN-SV-EXMX02.mchp-main.com> From: Florian Fainelli Message-ID: <508d7ef0-e351-5369-b477-b027bae3dda4@gmail.com> Date: Fri, 8 Sep 2017 12:54:01 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <93AF473E2DA327428DE3D46B72B1E9FD41121EF7@CHN-SV-EXMX02.mchp-main.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3102 Lines: 80 On 09/08/2017 12:48 PM, Tristram.Ha@microchip.com wrote: >> -----Original Message----- >> From: Maxim Uvarov [mailto:muvarov@gmail.com] >> Sent: Friday, September 08, 2017 12:00 PM >> To: Florian Fainelli >> Cc: Tristram Ha - C24268; Andrew Lunn; Pavel Machek; Nathan Conrad; Vivien >> Didelot; netdev; linux-kernel@vger.kernel.org; Woojung Huh - C21699 >> Subject: Re: [PATCH RFC] Update documentation for KSZ DSA drivers so that new >> drivers can be added >> >> 2017-09-08 21:48 GMT+03:00 Florian Fainelli : >>> On 09/07/2017 02:11 PM, Tristram.Ha@microchip.com wrote: >>>> From: Tristram Ha >>>> >>>> Add other KSZ switches support so that patch check does not complain. >>>> >>>> Signed-off-by: Tristram Ha >>>> --- >>>> Documentation/devicetree/bindings/net/dsa/ksz.txt | 117 >>>> ++++++++++++---------- >>>> 1 file changed, 62 insertions(+), 55 deletions(-) >>>> >>>> diff --git a/Documentation/devicetree/bindings/net/dsa/ksz.txt >>>> b/Documentation/devicetree/bindings/net/dsa/ksz.txt >>>> index 0ab8b39..34af0e0 100644 >>>> --- a/Documentation/devicetree/bindings/net/dsa/ksz.txt >>>> +++ b/Documentation/devicetree/bindings/net/dsa/ksz.txt >>>> @@ -3,8 +3,15 @@ Microchip KSZ Series Ethernet switches >>>> >>>> Required properties: >>>> >>>> -- compatible: For external switch chips, compatible string must be >>>> exactly one >>>> - of: "microchip,ksz9477" >>>> +- compatible: Should be "microchip,ksz9477" for KSZ9477 chip, >>>> + "microchip,ksz8795" for KSZ8795 chip, >>>> + "microchip,ksz8794" for KSZ8794 chip, >>>> + "microchip,ksz8765" for KSZ8765 chip, >>>> + "microchip,ksz8895" for KSZ8895 chip, >>>> + "microchip,ksz8864" for KSZ8864 chip, >>>> + "microchip,ksz8873" for KSZ8873 chip, >>>> + "microchip,ksz8863" for KSZ8863 chip, >>>> + "microchip,ksz8463" for KSZ8463 chip >>> >> >> >> Tristram, does any of this devices support chaining? >> >> Maxim. > > They do not if you mean daisy-chaining the switches together. Marvell tags allow you to specify both a port and switch index destination after setting up an appropriate routing table, I am assuming this is not supported. What happens though if I connect two KSZ switches ones to another say: eth0 -> KSZ8463 -> KSZ8463 Will the first switch terminates KSZ tag if it sees two tags encapsulated in another, something like this: | MAC DA | MAC SA | .... payload | Inner KSZ tag | Inner KSZ tag | FCS | > > There is always a problem that once tail tagging mode is enabled > sending a frame through the MAC without going through the DSA > layer will cause the frame to be dropped. Yes, once the master network device is used for DSA, it is still usable directly by e.g: applications, but it won't do anything if the switch is configured such that it drops ingressing frames not having the proper tag. We documented that here: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/networking/dsa/dsa.txt#n275 -- Florian