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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 F18F6C433E0 for ; Thu, 14 May 2020 20:49:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B48142065C for ; Thu, 14 May 2020 20:49:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727885AbgENUtV (ORCPT ); Thu, 14 May 2020 16:49:21 -0400 Received: from foss.arm.com ([217.140.110.172]:44304 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725975AbgENUtU (ORCPT ); Thu, 14 May 2020 16:49:20 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D64281042; Thu, 14 May 2020 13:49:19 -0700 (PDT) Received: from [192.168.122.166] (unknown [10.119.48.101]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8082E3F68F; Thu, 14 May 2020 13:49:19 -0700 (PDT) Subject: Re: [PATCH] net: phy: Fix c45 no phy detected logic To: Heiner Kallweit , netdev@vger.kernel.org Cc: andrew@lunn.ch, f.fainelli@gmail.com, linux@armlinux.org.uk, davem@davemloft.net, linux-kernel@vger.kernel.org References: <20200514170025.1379981-1-jeremy.linton@arm.com> From: Jeremy Linton Message-ID: <337071a2-0eaf-6143-f6c0-b451d681733d@arm.com> Date: Thu, 14 May 2020 15:49:18 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed 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 Hi, On 5/14/20 2:59 PM, Heiner Kallweit wrote: > On 14.05.2020 19:00, Jeremy Linton wrote: >> The commit "disregard Clause 22 registers present bit..." clears >> the low bit of the devices_in_package data which is being used >> in get_phy_c45_ids() to determine if a phy/register is responding >> correctly. That check is against 0x1FFFFFFF, but since the low >> bit is always cleared, the check can never be true. This leads to >> detecting c45 phy devices where none exist. >> >> Lets fix this by also clearing the low bit in the mask to 0x1FFFFFFE. >> This allows us to continue to autoprobe standards compliant devices >> without also gaining a large number of bogus ones. >> >> Fixes: 3b5e74e0afe3 ("net: phy: disregard "Clause 22 registers present" bit in get_phy_c45_devs_in_pkg") >> Cc: Heiner Kallweit >> Signed-off-by: Jeremy Linton >> --- >> drivers/net/phy/phy_device.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c >> index ac2784192472..b93d984d35cc 100644 >> --- a/drivers/net/phy/phy_device.c >> +++ b/drivers/net/phy/phy_device.c >> @@ -723,7 +723,7 @@ static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id, >> if (phy_reg < 0) >> return -EIO; >> >> - if ((*devs & 0x1fffffff) == 0x1fffffff) { >> + if ((*devs & 0x1ffffffe) == 0x1ffffffe) { >> /* If mostly Fs, there is no device there, > > Looks good to me, it would just be good to extend the comment and explain > why we exclude bit 0 here. Sure, sounds good. > > >> * then let's continue to probe more, as some >> * 10G PHYs have zero Devices In package, >> @@ -733,7 +733,7 @@ static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id, >> if (phy_reg < 0) >> return -EIO; >> /* no device there, let's get out of here */ >> - if ((*devs & 0x1fffffff) == 0x1fffffff) { >> + if ((*devs & 0x1ffffffe) == 0x1ffffffe) { >> *phy_id = 0xffffffff; >> return 0; >> } else { >> >