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=-2.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 8F2B5C3A5A1 for ; Wed, 28 Aug 2019 17:00:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 52E4822CF5 for ; Wed, 28 Aug 2019 17:00:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bv6EplGv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726749AbfH1RAH (ORCPT ); Wed, 28 Aug 2019 13:00:07 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:33550 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726428AbfH1RAH (ORCPT ); Wed, 28 Aug 2019 13:00:07 -0400 Received: by mail-pg1-f196.google.com with SMTP id n190so71076pgn.0; Wed, 28 Aug 2019 10:00:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:openpgp:autocrypt:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=decKtc/g5mKDxnU3M4CnjbopGl5p5ls3xyrkhWq75Ck=; b=bv6EplGvmRQzBpcYi+Vkq1yWLxlv2X7wue/xacuLKnEcSpUmOSv+ilHDanoSiOArW9 HzGijZK4WFbjrozxmTNL7COm4r5P5+Td9DazTuZ/zkWavR9kDU0K1cUX6yMsjXLEF+MN O0p0l5dsStPx/IRPj63FY44LY+SHHZFmxNsSBSbLMPKHOPtpGesSW0AqbTxbKYt1AQIs G7dcRUo1qYf4Ud9jorSVV4D+o49pMfSnhwC8W4VyAPP2gf4T87RrBMnLWodc/Ae0NyUP fcg6xoWni3WXj+MD8WaO3G0l/HFo+lgo8taCBtfpvtYByY1kp2ofTFxAzpC32YrudLWq mZug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:openpgp:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=decKtc/g5mKDxnU3M4CnjbopGl5p5ls3xyrkhWq75Ck=; b=i49Ryg9d93TE0OASPiV5JBk9MkkKt/UUubBkfVgp90WdNvmbpe0FpHpvnu1ScDCs1r ILtIT4YcU1SQBa2pI7H4+/5QrDhxqYMAOPq3S/+pMGUIgrB8mr0iPAQDpaV5Og2XXGL1 DboqvLjVWTpd8B/0b5AdntFOhFSmIw346ilhBEu8BS8OhW2ubsIlX8ubx6WuXaAryik/ m5Oagk2vvGkdA3kXIvxS8dlG4yoa8Ed02eeDjMVuUOXnz0LPP90H7c5mOs7ElGO7L7aY j4WMGK+EDt1kKnN2tmqIad4+a+qzP+FA/8o0L255lN8NfUHgbZB98iLf260Qbadi7fek ERgw== X-Gm-Message-State: APjAAAXl7BzV6VCvvv/rrUjARtpBsvXj61AboiOenV+CbPE/yGYKrtlD uKTZ+68542dd67p8zmgVfSs= X-Google-Smtp-Source: APXvYqyypedWBTazjZm8LOnMG0UBTWAl3VL5LhTz9b+j3K/ULPyjgSiTd5IqpJN9jMrUwVmn7chlNA== X-Received: by 2002:a17:90a:fa82:: with SMTP id cu2mr5384513pjb.85.1567011606288; Wed, 28 Aug 2019 10:00:06 -0700 (PDT) Received: from [10.67.49.31] ([192.19.223.252]) by smtp.googlemail.com with ESMTPSA id n24sm3139642pjq.21.2019.08.28.10.00.04 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 28 Aug 2019 10:00:05 -0700 (PDT) Subject: Re: [PATCH v1 net-next] net: phy: mdio_bus: make mdiobus_scan also cover PHY that only talks C45 To: "Ong, Boon Leong" , Andrew Lunn Cc: "David S. Miller" , Maxime Coquelin , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Jose Abreu , "Voon, Weifeng" , Heiner Kallweit References: <1566870769-9967-1-git-send-email-weifeng.voon@intel.com> <20190826185418.GG2168@lunn.ch> <20190827154918.GO2168@lunn.ch> From: Florian Fainelli Openpgp: preference=signencrypt Autocrypt: addr=f.fainelli@gmail.com; prefer-encrypt=mutual; keydata= mQGiBEjPuBIRBACW9MxSJU9fvEOCTnRNqG/13rAGsj+vJqontvoDSNxRgmafP8d3nesnqPyR xGlkaOSDuu09rxuW+69Y2f1TzjFuGpBk4ysWOR85O2Nx8AJ6fYGCoeTbovrNlGT1M9obSFGQ X3IzRnWoqlfudjTO5TKoqkbOgpYqIo5n1QbEjCCwCwCg3DOH/4ug2AUUlcIT9/l3pGvoRJ0E AICDzi3l7pmC5IWn2n1mvP5247urtHFs/uusE827DDj3K8Upn2vYiOFMBhGsxAk6YKV6IP0d ZdWX6fqkJJlu9cSDvWtO1hXeHIfQIE/xcqvlRH783KrihLcsmnBqOiS6rJDO2x1eAgC8meAX SAgsrBhcgGl2Rl5gh/jkeA5ykwbxA/9u1eEuL70Qzt5APJmqVXR+kWvrqdBVPoUNy/tQ8mYc nzJJ63ng3tHhnwHXZOu8hL4nqwlYHRa9eeglXYhBqja4ZvIvCEqSmEukfivk+DlIgVoOAJbh qIWgvr3SIEuR6ayY3f5j0f2ejUMYlYYnKdiHXFlF9uXm1ELrb0YX4GMHz7QnRmxvcmlhbiBG YWluZWxsaSA8Zi5mYWluZWxsaUBnbWFpbC5jb20+iGYEExECACYCGyMGCwkIBwMCBBUCCAME FgIDAQIeAQIXgAUCVF/S8QUJHlwd3wAKCRBhV5kVtWN2DvCVAJ4u4/bPF4P3jxb4qEY8I2gS 6hG0gACffNWlqJ2T4wSSn+3o7CCZNd7SLSC5BA0ESM+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 y5arMQorqTFWlEOgRA8OP47L9knl9i4xuR0euV6DChDrguup2aJVU4hPBBgRAgAPAhsMBQJU X9LxBQkeXB3fAAoJEGFXmRW1Y3YOj4UAn3nrFLPZekMeqX5aD/aq/dsbXSfyAKC45Go0YyxV HGuUuzv+GKZ6nsysJ7kCDQRXG8fwARAA6q/pqBi5PjHcOAUgk2/2LR5LjjesK50bCaD4JuNc YDhFR7Vs108diBtsho3w8WRd9viOqDrhLJTroVckkk74OY8r+3t1E0Dd4wHWHQZsAeUvOwDM PQMqTUBFuMi6ydzTZpFA2wBR9x6ofl8Ax+zaGBcFrRlQnhsuXLnM1uuvS39+pmzIjasZBP2H UPk5ifigXcpelKmj6iskP3c8QN6x6GjUSmYx+xUfs/GNVSU1XOZn61wgPDbgINJd/THGdqiO iJxCLuTMqlSsmh1+E1dSdfYkCb93R/0ZHvMKWlAx7MnaFgBfsG8FqNtZu3PCLfizyVYYjXbV WO1A23riZKqwrSJAATo5iTS65BuYxrFsFNPrf7TitM8E76BEBZk0OZBvZxMuOs6Z1qI8YKVK UrHVGFq3NbuPWCdRul9SX3VfOunr9Gv0GABnJ0ET+K7nspax0xqq7zgnM71QEaiaH17IFYGS sG34V7Wo3vyQzsk7qLf9Ajno0DhJ+VX43g8+AjxOMNVrGCt9RNXSBVpyv2AMTlWCdJ5KI6V4 KEzWM4HJm7QlNKE6RPoBxJVbSQLPd9St3h7mxLcne4l7NK9eNgNnneT7QZL8fL//s9K8Ns1W t60uQNYvbhKDG7+/yLcmJgjF74XkGvxCmTA1rW2bsUriM533nG9gAOUFQjURkwI8jvMAEQEA AYkCaAQYEQIACQUCVxvH8AIbAgIpCRBhV5kVtWN2DsFdIAQZAQIABgUCVxvH8AAKCRCH0Jac RAcHBIkHD/9nmfog7X2ZXMzL9ktT++7x+W/QBrSTCTmq8PK+69+INN1ZDOrY8uz6htfTLV9+ e2W6G8/7zIvODuHk7r+yQ585XbplgP0V5Xc8iBHdBgXbqnY5zBrcH+Q/oQ2STalEvaGHqNoD UGyLQ/fiKoLZTPMur57Fy1c9rTuKiSdMgnT0FPfWVDfpR2Ds0gpqWePlRuRGOoCln5GnREA/ 2MW2rWf+CO9kbIR+66j8b4RUJqIK3dWn9xbENh/aqxfonGTCZQ2zC4sLd25DQA4w1itPo+f5 V/SQxuhnlQkTOCdJ7b/mby/pNRz1lsLkjnXueLILj7gNjwTabZXYtL16z24qkDTI1x3g98R/ xunb3/fQwR8FY5/zRvXJq5us/nLvIvOmVwZFkwXc+AF+LSIajqQz9XbXeIP/BDjlBNXRZNdo dVuSU51ENcMcilPr2EUnqEAqeczsCGpnvRCLfVQeSZr2L9N4svNhhfPOEscYhhpHTh0VPyxI pPBNKq+byuYPMyk3nj814NKhImK0O4gTyCK9b+gZAVvQcYAXvSouCnTZeJRrNHJFTgTgu6E0 caxTGgc5zzQHeX67eMzrGomG3ZnIxmd1sAbgvJUDaD2GrYlulfwGWwWyTNbWRvMighVdPkSF 6XFgQaosWxkV0OELLy2N485YrTr2Uq64VKyxpncLh50e2RnyAJ9Za0Dx0yyp44iD1OvHtkEI M5kY0ACeNhCZJvZ5g4C2Lc9fcTHu8jxmEkI= Message-ID: Date: Wed, 28 Aug 2019 10:00:00 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 8/28/19 8:41 AM, Ong, Boon Leong wrote: >> On Tue, Aug 27, 2019 at 03:23:34PM +0000, Voon, Weifeng wrote: >>>>>> Make mdiobus_scan() to try harder to look for any PHY that only >>>> talks C45. >>>>> If you are not using Device Tree or ACPI, and you are letting the MDIO >>>>> bus be scanned, it sounds like there should be a way for you to >>>>> provide a hint as to which addresses should be scanned (that's >>>>> mii_bus::phy_mask) and possibly enhance that with a mask of possible >>>>> C45 devices? >>>> >>>> Yes, i don't like this unconditional c45 scanning. A lot of MDIO bus >>>> drivers don't look for the MII_ADDR_C45. They are going to do a C22 >>>> transfer, and maybe not mask out the MII_ADDR_C45 from reg, causing an >>>> invalid register write. Bad things can then happen. >>>> >>>> With DT and ACPI, we have an explicit indication that C45 should be used, >>>> so we know on this platform C45 is safe to use. We need something >>>> similar when not using DT or ACPI. >>>> >>>> Andrew >>> >>> Florian and Andrew, >>> The mdio c22 is using the start-of-frame ST=01 while mdio c45 is using ST=00 >>> as identifier. So mdio c22 device will not response to mdio c45 protocol. >>> As in IEEE 802.1ae-2002 Annex 45A.3 mention that: >>> " Even though the Clause 45 MDIO frames using the ST=00 frame code >>> will also be driven on to the Clause 22 MII Management interface, >>> the Clause 22 PHYs will ignore the frames. " >>> >>> Hence, I am not seeing any concern that the c45 scanning will mess up with >>> c22 devices. >> >> Hi Voon >> >> Take for example mdio-hisi-femac.c >> >> static int hisi_femac_mdio_read(struct mii_bus *bus, int mii_id, int regnum) >> { >> struct hisi_femac_mdio_data *data = bus->priv; >> int ret; >> >> ret = hisi_femac_mdio_wait_ready(data); >> if (ret) >> return ret; >> >> writel((mii_id << BIT_PHY_ADDR_OFFSET) | regnum, >> data->membase + MDIO_RWCTRL); >> >> >> There is no check here for MII_ADDR_C45. So it will perform a C22 >> transfer. And regnum will still have MII_ADDR_C45 in it, so the >> writel() is going to set bit 30, since #define MII_ADDR_C45 >> (1<<30). What happens on this hardware under these conditions? >> >> You cannot unconditionally ask an MDIO driver to do a C45 >> transfer. Some drivers are going to do bad things. > > Andrew & Florian, thanks for your review on this patch and insights on it. > We will look into the implementation as suggested as follow. > > - for each bit clear in mii_bus::phy_mask, scan it as C22 > - for each bit clear in mii_bus::phy_c45_mask, scan it as C45 > > We will work on this and resubmit soonest. Sounds good. If you do not need to scan the MDIO bus, another approach is to call get_phy_device() by passing the is_c45 boolean to true in order to connect directly to a C45 device for which you already know the address. Assuming this is done for the stmmac PCI changes that you have submitted, and that those cards have a fixed set of addresses for their PHYs, maybe scanning the bus is overkill? -- Florian