Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932290AbbGJSYp (ORCPT ); Fri, 10 Jul 2015 14:24:45 -0400 Received: from mail-pd0-f181.google.com ([209.85.192.181]:34755 "EHLO mail-pd0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932287AbbGJSYf (ORCPT ); Fri, 10 Jul 2015 14:24:35 -0400 Message-ID: <55A00D7C.9090807@gmail.com> Date: Fri, 10 Jul 2015 11:22:52 -0700 From: Florian Fainelli User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Stas Sergeev , Sebastien Rannou CC: Linux kernel , Arnaud Ebalard , Stas Sergeev , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Grant Likely , devicetree@vger.kernel.org, netdev , Thomas Petazzoni Subject: Re: [PATCH 1/2] of_mdio: add new DT property 'link' for fixed-link References: <559EB0A4.5080101@list.ru> <559EB1A6.1090008@list.ru> <559EBC59.6020003@gmail.com> <559EDD0C.7020907@list.ru> <559EE45C.4040408@gmail.com> <559EEAE9.4000806@list.ru> <559FAA71.2030209@list.ru> In-Reply-To: <559FAA71.2030209@list.ru> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2465 Lines: 64 On 10/07/15 04:20, Stas Sergeev wrote: > 10.07.2015 11:46, Sebastien Rannou пишет: >> On Fri, 10 Jul 2015, Stas Sergeev wrote: >> >>> 10.07.2015 00:15, Florian Fainelli пишет: >>>> Then, if the in-band status indication is not reliable (which really >>>> should be completely understood), >>> Agree! >>> But this is not something I can help with. >>> Sebastien Rannou reports the problem, please ask him whatever >>> you see fits to get a better understanding of a problem. >>> The fact that his HW does not generate the inband status, is >>> _my own guess_. >> >> Yes, I confirm that my HW does not generate an in-band status. AFAIK, it's >> a PHY that aggregates 4xSGMIIs to 1xQSGMII ; the MAC side of the PHY (with >> inband status) is connected to the switch through QSGMII, and in this context >> we are on the media side of the PHY. > Hmm, interesting. > So if I parse the above correctly, you have something like 88E1340S set > up into a mode when SGMII is used as media interface and QSGMII as system > interface (terms are from datasheet page 5), then you connect the media > interface to armada-xp and system interface to the switch. > > I wonder if it is the right thing to do. > AFAIK you could as well set up armada-xp into QSGMII mode and connect > that to switch. The driver would then disable the use of inband status > and everything would be fine. > Either way, your use-case proves that only DT can decide the use of an > inband status. I do not think there is any debate around the need for a property that defines whether in-band-status is both reliable and usable, the debate is about *where* to put it. I still think this does not belong in the fixed-link property, but now that you have explained a bit more in the other patch what your understanding of "fixed-link" is, I can see the confusion. Instead of having a link = "auto", property, how about just something like this: fixed-link { speed = <1000>; full-duplex; use-in-band-status; }; or event this: fixed-link { use-in-band-status; }; If you parse the 'use-in-band-status' which means that it is reliable information, then you can override whatever was defined in the DT under the 'fixed-link' property? -- Florian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/