From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 80AB9C3279B for ; Fri, 6 Jul 2018 18:41:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 233DA21527 for ; Fri, 6 Jul 2018 18:41:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="cO79ZKVF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 233DA21527 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934461AbeGFSl3 (ORCPT ); Fri, 6 Jul 2018 14:41:29 -0400 Received: from mail-wr1-f66.google.com ([209.85.221.66]:34059 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934112AbeGFSl1 (ORCPT ); Fri, 6 Jul 2018 14:41:27 -0400 Received: by mail-wr1-f66.google.com with SMTP id c13-v6so5013629wrt.1; Fri, 06 Jul 2018 11:41:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:openpgp:autocrypt:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=1KWO5GdKgR7n0a/u5iMWpW4chwxTqjo+WjjPLSZuXKI=; b=cO79ZKVFPVjDsarMDWJzTuxcW0RvowocjbDb4P2tpIqj8KFxcygutvPwe16LcTjqu6 MSs79LUkd+uEKiSHtlBy3vTGiv4pajjXdEBLf+WsDGfXfShWMAIlpJ4jP9i5M2wauAbZ YunPqR88dSzQFn9YBttWAILJzbUBRoJI86uMLPdfSRw/YYz/rUaWt9DQ5IAjCKOCHExx 8vEIknaFKSO89DmhWbAKubXLCAOeXsznXN4B95iKiKPjuIConPD4k6pBc6W0t9KHG5Ya RwCcUU6ZsZ//qz9+TefODCm4VP+1+Yxcu0G3if64okfImb6FdNCb6FhDb+rv8iC+dbAS LuAQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:openpgp:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=1KWO5GdKgR7n0a/u5iMWpW4chwxTqjo+WjjPLSZuXKI=; b=OStsL1Fh5JIjV3GSVMcrkKdoRsELFq8QCa4WrjApSk38/C0whdotGju8nCY98J8Ef2 HdbzMbNfowImIT5CkPK7ZbPaXqosGY717D6EI7lfhQyvMKpTOdhcMq7YPowhxxzlrYJy JqpL8x3r5q9xGKOdQvm4/JLJiN61B0JL7JiUOtkeGdAbpvCfs3apzxNLAmBohZ15SzoS ZcQ7EUMqnp/UVeb7TBRkzI7YyudPDqBi9P+D+CNzUYBfXdFbkC9BHDYJHn0YvNUNCk6F 2JjNPK3NXoTyilULyENbKIP3taI7paP74EFnHQl1gLtvB/p47R+7pOmq4TnORhOq9pFu CdGw== X-Gm-Message-State: APt69E2uqVHa4225mZ6X9CI442hStcD4C6kEdB/pgV9rpxmIqcysjaVU +BRJqJxlGM0dFhGNL4ae/X8= X-Google-Smtp-Source: AAOMgpegTGaDhv4SmsyqqsNi0675f/dKKyw8O/Js/Sacn7NT2Z2J5X9Sp2ShqmFGy90ESO7T4VVxVA== X-Received: by 2002:a5d:4091:: with SMTP id o17-v6mr7642914wrp.133.1530902486075; Fri, 06 Jul 2018 11:41:26 -0700 (PDT) Received: from [192.168.1.14] (ARennes-658-1-259-104.w92-135.abo.wanadoo.fr. [92.135.242.104]) by smtp.gmail.com with ESMTPSA id b33-v6sm238977wrg.45.2018.07.06.11.41.24 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 06 Jul 2018 11:41:24 -0700 (PDT) Subject: Re: [RFC PATCH 0/1] net: phy: skip autoneg of ethernet(fec) on network boot To: Masahiko Kimoto , Fugang Duan , Andrew Lunn , netdev@vger.kernel.org, Linux Kernel Mailing List , Hiraku Toyooka References: <1530857230-31124-1-git-send-email-masahiko.kimoto@cybertrust.co.jp> From: Florian Fainelli Openpgp: preference=signencrypt Autocrypt: addr=f.fainelli@gmail.com; prefer-encrypt=mutual; keydata= xsDiBEjPuBIRBACW9MxSJU9fvEOCTnRNqG/13rAGsj+vJqontvoDSNxRgmafP8d3nesnqPyR xGlkaOSDuu09rxuW+69Y2f1TzjFuGpBk4ysWOR85O2Nx8AJ6fYGCoeTbovrNlGT1M9obSFGQ X3IzRnWoqlfudjTO5TKoqkbOgpYqIo5n1QbEjCCwCwCg3DOH/4ug2AUUlcIT9/l3pGvoRJ0E AICDzi3l7pmC5IWn2n1mvP5247urtHFs/uusE827DDj3K8Upn2vYiOFMBhGsxAk6YKV6IP0d ZdWX6fqkJJlu9cSDvWtO1hXeHIfQIE/xcqvlRH783KrihLcsmnBqOiS6rJDO2x1eAgC8meAX SAgsrBhcgGl2Rl5gh/jkeA5ykwbxA/9u1eEuL70Qzt5APJmqVXR+kWvrqdBVPoUNy/tQ8mYc nzJJ63ng3tHhnwHXZOu8hL4nqwlYHRa9eeglXYhBqja4ZvIvCEqSmEukfivk+DlIgVoOAJbh qIWgvr3SIEuR6ayY3f5j0f2ejUMYlYYnKdiHXFlF9uXm1ELrb0YX4GMHz80nRmxvcmlhbiBG YWluZWxsaSA8Zi5mYWluZWxsaUBnbWFpbC5jb20+wmYEExECACYCGyMGCwkIBwMCBBUCCAME FgIDAQIeAQIXgAUCVF/S8QUJHlwd3wAKCRBhV5kVtWN2DvCVAJ4u4/bPF4P3jxb4qEY8I2gS 6hG0gACffNWlqJ2T4wSSn+3o7CCZNd7SLSDOw00ESM+4EhAQAL/o09boR9D3Vk1Tt7+gpYr3 WQ6hgYVON905q2ndEoA2J0dQxJNRw3snabHDDzQBAcqOvdi7YidfBVdKi0wxHhSuRBfuOppu pdXkb7zxuPQuSveCLqqZWRQ+Cc2QgF7SBqgznbe6Ngout5qXY5Dcagk9LqFNGhJQzUGHAsIs hap1f0B1PoUyUNeEInV98D8Xd/edM3mhO9nRpUXRK9Bvt4iEZUXGuVtZLT52nK6Wv2EZ1TiT OiqZlf1P+vxYLBx9eKmabPdm3yjalhY8yr1S1vL0gSA/C6W1o/TowdieF1rWN/MYHlkpyj9c Rpc281gAO0AP3V1G00YzBEdYyi0gaJbCEQnq8Vz1vDXFxHzyhgGz7umBsVKmYwZgA8DrrB0M oaP35wuGR3RJcaG30AnJpEDkBYHznI2apxdcuTPOHZyEilIRrBGzDwGtAhldzlBoBwE3Z3MY 31TOpACu1ZpNOMysZ6xiE35pWkwc0KYm4hJA5GFfmWSN6DniimW3pmdDIiw4Ifcx8b3mFrRO BbDIW13E51j9RjbO/nAaK9ndZ5LRO1B/8Fwat7bLzmsCiEXOJY7NNpIEpkoNoEUfCcZwmLrU +eOTPzaF6drw6ayewEi5yzPg3TAT6FV3oBsNg3xlwU0gPK3v6gYPX5w9+ovPZ1/qqNfOrbsE FRuiSVsZQ5s3AAMFD/9XjlnnVDh9GX/r/6hjmr4U9tEsM+VQXaVXqZuHKaSmojOLUCP/YVQo 7IiYaNssCS4FCPe4yrL4FJJfJAsbeyDykMN7wAnBcOkbZ9BPJPNCbqU6dowLOiy8AuTYQ48m vIyQ4Ijnb6GTrtxIUDQeOBNuQC/gyyx3nbL/lVlHbxr4tb6YkhkO6shjXhQh7nQb33FjGO4P WU11Nr9i/qoV8QCo12MQEo244RRA6VMud06y/E449rWZFSTwGqb0FS0seTcYNvxt8PB2izX+ HZA8SL54j479ubxhfuoTu5nXdtFYFj5Lj5x34LKPx7MpgAmj0H7SDhpFWF2FzcC1bjiW9mjW HaKaX23Awt97AqQZXegbfkJwX2Y53ufq8Np3e1542lh3/mpiGSilCsaTahEGrHK+lIusl6mz Joil+u3k01ofvJMK0ZdzGUZ/aPMZ16LofjFA+MNxWrZFrkYmiGdv+LG45zSlZyIvzSiG2lKy kuVag+IijCIom78P9jRtB1q1Q5lwZp2TLAJlz92DmFwBg1hyFzwDADjZ2nrDxKUiybXIgZp9 aU2d++ptEGCVJOfEW4qpWCCLPbOT7XBr+g/4H3qWbs3j/cDDq7LuVYIe+wchy/iXEJaQVeTC y5arMQorqTFWlEOgRA8OP47L9knl9i4xuR0euV6DChDrguup2aJVU8JPBBgRAgAPAhsMBQJU X9LxBQkeXB3fAAoJEGFXmRW1Y3YOj4UAn3nrFLPZekMeqX5aD/aq/dsbXSfyAKC45Go0YyxV HGuUuzv+GKZ6nsysJw== Message-ID: <8a437ead-5ded-57c4-c44f-95986442d626@gmail.com> Date: Fri, 6 Jul 2018 11:41:23 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <1530857230-31124-1-git-send-email-masahiko.kimoto@cybertrust.co.jp> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/05/2018 11:07 PM, Masahiko Kimoto wrote: > Hello, > > This patch introduces auto negotiation skipping for Ethernet. > It is useful to shorten boot time on network boot like the following > environment; > > - target board is NXP i.MX6. > - NIC is fec. > - using u-boot as boot loader. > - boot from kernel and initramfs obtained via TFTP. > - mount remote file system and switch root to that. > - thus all file system is on network. > > In this case, u-boot and kernel initialize NIC three times, > once in boot loader, once in device attach and once more in phy attach. > Each causes link auto negotiation and wait several seconds. > However link state is stable after reset by boot loader, therefore we > can skip hardware re-initialization of NIC in kernel. > > The patch skips link down in Ethernet(i.MX's fec) driver and initialization > in PHY layer if kernel option 'anegskip' is supplied. > > By this patch boot time becomes 3secs shorter. > > I think current patch is dirty hack, because; > - modification is split into PHY and Ethernet driver. > - in the case of two or more Ethernet I/F exist, currently there is > no way to specify whith I/F skips autonego. > > I would like to implement such skpping auto negotiation feature in generic > framework. How should we implement these requirements? I completely acknowledge and support the use case, but your implementation is definitively not the way to go. In my experience the problem is usually that there may be a disagreement on the Pause/Asym_Pause advertisement bits and that alone is responsible for triggering a re-negotiation. Can yo check if that is the case here? Thank you -- Florian