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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BF172C00140 for ; Mon, 15 Aug 2022 18:09:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232994AbiHOSJS (ORCPT ); Mon, 15 Aug 2022 14:09:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53564 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230266AbiHOSJQ (ORCPT ); Mon, 15 Aug 2022 14:09:16 -0400 Received: from mail-qv1-xf32.google.com (mail-qv1-xf32.google.com [IPv6:2607:f8b0:4864:20::f32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A473529C8C; Mon, 15 Aug 2022 11:09:15 -0700 (PDT) Received: by mail-qv1-xf32.google.com with SMTP id y4so4970581qvr.7; Mon, 15 Aug 2022 11:09:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc; bh=35BvP9EA6UmVAWVwUm9hFAUDuAeF8dpNkQ9qW8oNTB4=; b=jucWJuC9qvN4lki55uHyX7PERPzNfa8Ji9ed4mbdY+F/XjglZn2GS7DRSSM+I7gJXy g2VDVCt1NnVqNvvKnXGyo2pZoRIGsnX7nHdAaUHkJWPHWkXEmecqnED6ivmXkFiQKd0L W55Rk+XQcZ2OmU8qyarBDhNEx+K5nrOivVqxQEOIcI6G7gzY7mZ5a6p3iqXgFo/GLjEK z26wmO0X/876nBR/pc0D4H+lWpd07379rjcxzwQdb2zs+iXBFgVCkFgTAN4Bt3gxvZl8 T6ap+6R6ZagOxUtirf2ezRrbk486i7SKOa3xK6nac5LqbXsQnxrovv0B7yIdfJ3NIZdD OXWA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc; bh=35BvP9EA6UmVAWVwUm9hFAUDuAeF8dpNkQ9qW8oNTB4=; b=0fLKLYm8nUInd+Ele9Dcg34pAaeO0fPoOCksXQqIwFycxmuwMSpnKVI+ywqZRUmQMr gR39zalJTRFsFZM/WtC9ios0xoAGA/FO6Y1qW5KCVeKHOOdoalQYFcGgrCWrnlBhzMAC 8v4Fre6T2RiUkjUPPfcV8gWA7IXQaWJs2YJfJ/0QekXDtvo2MgFTrOG05rNHhbAfsDGP AvgHSAomcYlxP83sG8XacTITRT3XPf2elE80ht7YND/G8zYB88AYnuCs+xx7LcNyyvY/ AoLdlgX42niHMrLsn66xReNEnS3H5OWzV8z97hLf1whM/p8C9SSoejblGeqg/kilNm8f zC3A== X-Gm-Message-State: ACgBeo3wLpRCO7er1A2TN+HEtbK8siWRVzxyUQGGzCRA9SqJruNrOO5/ pb/I2RWTsbg8RiIIkfK7KXg= X-Google-Smtp-Source: AA6agR4haNDihliJMwbXVir8pO28zMsz56l90jSW3Mrz4IaeRNTqrPLvDHHY5cfuqsqbOgCBV6Bl0g== X-Received: by 2002:a05:6214:2a84:b0:476:feb2:f436 with SMTP id jr4-20020a0562142a8400b00476feb2f436mr14623928qvb.43.1660586954722; Mon, 15 Aug 2022 11:09:14 -0700 (PDT) Received: from [10.67.48.245] ([192.19.223.252]) by smtp.googlemail.com with ESMTPSA id y23-20020ac87c97000000b00342f8984348sm8360320qtv.87.2022.08.15.11.09.13 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 15 Aug 2022 11:09:14 -0700 (PDT) Message-ID: Date: Mon, 15 Aug 2022 11:09:11 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH net-next] net: phy: broadcom: Implement suspend/resume for AC131 and BCM5241 Content-Language: en-US To: "Russell King (Oracle)" , Florian Fainelli Cc: netdev@vger.kernel.org, Broadcom internal kernel review list , Andrew Lunn , Heiner Kallweit , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , open list References: <20220815174356.2681127-1-f.fainelli@gmail.com> From: Florian Fainelli In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/15/22 11:00, Russell King (Oracle) wrote: > On Mon, Aug 15, 2022 at 10:43:56AM -0700, Florian Fainelli wrote: >> + /* We cannot use a read/modify/write here otherwise the PHY continues >> + * to drive LEDs which defeats the purpose of low power mode. >> + */ > ... >> + /* Set standby mode */ >> + reg = phy_read(phydev, MII_BRCM_FET_SHDW_AUXMODE4); >> + if (reg < 0) { >> + err = reg; >> + goto done; >> + } >> + >> + reg |= MII_BRCM_FET_SHDW_AM4_STANDBY; >> + >> + err = phy_write(phydev, MII_BRCM_FET_SHDW_AUXMODE4, reg); > > Does the read-modify-write problem extend to this register? Why would > the PHY behave differently whether you used phy_modify() here or not? > On the mdio bus, it should be exactly the same - the only difference > is that we're guaranteed to hold the lock over the sequence whereas > this drops and re-acquires the lock. What read-modify-write problem are you referring to, that is, are you talking about my statement about setting BMCR.PDOWN only or something else? I could use phy_modify(), sure. -- Florian