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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 E2B0CC56202 for ; Thu, 26 Nov 2020 01:15:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8472B2075A for ; Thu, 26 Nov 2020 01:15:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730677AbgKZBPE (ORCPT ); Wed, 25 Nov 2020 20:15:04 -0500 Received: from szxga02-in.huawei.com ([45.249.212.188]:2444 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729131AbgKZBPE (ORCPT ); Wed, 25 Nov 2020 20:15:04 -0500 Received: from dggeme760-chm.china.huawei.com (unknown [172.30.72.57]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4ChKYD6vgTz4yNM; Thu, 26 Nov 2020 09:14:40 +0800 (CST) Received: from [127.0.0.1] (10.57.36.170) by dggeme760-chm.china.huawei.com (10.3.19.106) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1913.5; Thu, 26 Nov 2020 09:15:01 +0800 Subject: Re: [PATCH v3 net-next] net: phy: realtek: read actual speed on rtl8211f to detect downshift To: Russell King - ARM Linux admin CC: Antonio Borneo , Andrew Lunn , Heiner Kallweit , "David S. Miller" , Jakub Kicinski , , Willy Liu , , Salil Mehta , , References: <20201124143848.874894-1-antonio.borneo@st.com> <20201124230756.887925-1-antonio.borneo@st.com> <20201125170714.GK1551@shell.armlinux.org.uk> From: Yonglong Liu Message-ID: <3fdb1d11-d59e-9d3d-a5a8-8f20e4ca7f0a@huawei.com> Date: Thu, 26 Nov 2020 09:15:01 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.0.1 MIME-Version: 1.0 In-Reply-To: <20201125170714.GK1551@shell.armlinux.org.uk> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Originating-IP: [10.57.36.170] X-ClientProxiedBy: dggeme715-chm.china.huawei.com (10.1.199.111) To dggeme760-chm.china.huawei.com (10.3.19.106) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Russell:     I found this message in kernel log, thanks! On 2020/11/26 1:07, Russell King - ARM Linux admin wrote: > On Thu, Nov 26, 2020 at 12:57:37AM +0800, Yonglong Liu wrote: >> Hi, Antonio: >> >>     Could you help to provide a downshift warning message when this happen? >> >>     It's a little strange that the adv and the lpa support 1000M, but >> finally the link speed is 100M. > That is an identifying feature of downshift. > > Downshift can happen at either end of the link, and since we must not > change the "Advertised link modes" since this is what userspace > configured, if a downshift occurs at the local end, then you will get > the ethtool output you provide, where the speed does not agree with > the reported advertisements. > > You should already be getting a warning in the kernel log when this > happens; phy_check_downshift() which is part of the phylib core code > will check this every time the link comes up. You should already > have a message "Downshift occurred ..." in your kernel log. Please > check. >