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=-2.1 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, URIBL_BLOCKED,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 29791C2BB1D for ; Tue, 14 Apr 2020 04:05:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E9C82206D5 for ; Tue, 14 Apr 2020 04:05:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="szpE27qR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405096AbgDNEFy (ORCPT ); Tue, 14 Apr 2020 00:05:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54756 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S2405082AbgDNEFw (ORCPT ); Tue, 14 Apr 2020 00:05:52 -0400 Received: from mail-pg1-x542.google.com (mail-pg1-x542.google.com [IPv6:2607:f8b0:4864:20::542]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2AC29C0A3BDC; Mon, 13 Apr 2020 21:05:52 -0700 (PDT) Received: by mail-pg1-x542.google.com with SMTP id x26so4262241pgc.10; Mon, 13 Apr 2020 21:05:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:autocrypt:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=57wR7JG4KovsCDlh+sC4csFKRuPvrO4meeh+YvRdIVk=; b=szpE27qROKvKU7yT3f0u05s9ZgCO+p9oVjdTeFrdL5C4/FpuclODtYuncaEZ6ljX/X /IOPK1GgCHp2vMraThc/t6GsOkVLWKV/hVxP9DJYIqt/DlT9vHqzrgnLN1vt0Rlk/aFX YhWHyOrgjBlpITRvNjw/lvcmhj9e5xkTTpmqx9k1ZLFXTWc55TtkawHHciipO6SDVrwb ZpAHH7CBnz29dfk0GFIBUrpQs26tL4WlBhaXgeSgePToQEyecwI8C/45NMuEXeqsqPJD B9JETxuNVkdzmEj3NxQiuPS6+ipf2J0dmnbZYO+vqQq4mQX+kXcR1Ppgi8QpIHn18eb4 Q0HA== 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:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=57wR7JG4KovsCDlh+sC4csFKRuPvrO4meeh+YvRdIVk=; b=JiVZbIRXb7cyRFZuOO3MkPJuGAp4MyRzJMrQ/lWwv0Ie/YjTtZoUQ6daFPhFDyJ5Uh HeaddPvBJlZftdKbrDVZ2O462WPZ9leGwjboREILHiBWu6Qy4Yaw1D1Uff2++C+rAuAl Rxo34iMi4NnseT2QYPe4pIurEtd1VI4htt+ogOxMpiOyRkh+PrDiprbLnqDgbFgmnJkP fvRyIIY1TRfM+jK8yKL5jAhz1mVbQYT4EJ1LMzdndlj8RBO94CTcqt8qKsC0JmZHzKNq ECq4HyV4lEoQw2+M3oQax4r9St6PfErKq8ONc5cqawv0zfhq1z7OweJIfZbtcVe2cLWo e+Lw== X-Gm-Message-State: AGi0PubAEp0FRJqa8kit9Zn2l6vYP3i17JDpyOEYTCX30a+R4B63X7Eo 4BeDEoWWGPTLF9HAGpwl87Qbh60k X-Google-Smtp-Source: APiQypKChFmlWATB+qew24ZmMb6ujy8tXZXTanSdaJA5SK9tcudccbhcUthmmgIwSmVF3pF6I38tTA== X-Received: by 2002:a63:b952:: with SMTP id v18mr15018095pgo.179.1586837151624; Mon, 13 Apr 2020 21:05:51 -0700 (PDT) Received: from [10.230.188.26] ([192.19.223.252]) by smtp.gmail.com with ESMTPSA id t123sm9977679pfd.48.2020.04.13.21.05.49 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 13 Apr 2020 21:05:50 -0700 (PDT) Subject: Re: [PATCH net] net: stmmac: Guard against txfifosz=0 To: Chen-Yu Tsai , Jose Abreu Cc: Jakub Kicinski , Alexandre Torgue , "netdev@vger.kernel.org" , open list , "mripard@kernel.org" , "moderated list:ARM/STM32 ARCHITECTURE" , Maxime Coquelin , Giuseppe Cavallaro , "olteanv@gmail.com" , "David S. Miller" , "moderated list:ARM/STM32 ARCHITECTURE" References: <20200412034931.9558-1-f.fainelli@gmail.com> <20200412112756.687ff227@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> From: Florian Fainelli Autocrypt: addr=f.fainelli@gmail.com; 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: Mon, 13 Apr 2020 21:05:48 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Firefox/68.0 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 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 4/13/2020 6:49 PM, Chen-Yu Tsai wrote: > On Mon, Apr 13, 2020 at 2:59 PM Jose Abreu wrote: >> >> From: Chen-Yu Tsai >> Date: Apr/13/2020, 07:50:47 (UTC+00:00) >> >>> On Mon, Apr 13, 2020 at 2:42 PM Jose Abreu wrote: >>>> >>>> From: Florian Fainelli >>>> Date: Apr/12/2020, 19:31:55 (UTC+00:00) >>>> >>>>> >>>>> >>>>> On 4/12/2020 11:27 AM, Jakub Kicinski wrote: >>>>>> On Sat, 11 Apr 2020 20:49:31 -0700 Florian Fainelli wrote: >>>>>>> After commit bfcb813203e619a8960a819bf533ad2a108d8105 ("net: dsa: >>>>>>> configure the MTU for switch ports") my Lamobo R1 platform which uses >>>>>>> an allwinner,sun7i-a20-gmac compatible Ethernet MAC started to fail >>>>>>> by rejecting a MTU of 1536. The reason for that is that the DMA >>>>>>> capabilities are not readable on this version of the IP, and there is >>>>>>> also no 'tx-fifo-depth' property being provided in Device Tree. The >>>>>>> property is documented as optional, and is not provided. >>>>>>> >>>>>>> The minimum MTU that the network device accepts is ETH_ZLEN - ETH_HLEN, >>>>>>> so rejecting the new MTU based on the txfifosz value unchecked seems a >>>>>>> bit too heavy handed here. >>>>>> >>>>>> OTOH is it safe to assume MTUs up to 16k are valid if device tree lacks >>>>>> the optional property? Is this change purely to preserve backward >>>>>> (bug-ward?) compatibility, even if it's not entirely correct to allow >>>>>> high MTU values? (I think that'd be worth stating in the commit message >>>>>> more explicitly.) Is there no "reasonable default" we could select for >>>>>> txfifosz if property is missing? >>>>> >>>>> Those are good questions, and I do not know how to answer them as I am >>>>> not familiar with the stmmac HW design, but I am hoping Jose can respond >>>>> on this patch. It does sound like providing a default TX FIFO size would >>>>> solve that MTU problem, too, but without a 'tx-fifo-depth' property >>>>> specified in Device Tree, and with the "dma_cap" being empty for this >>>>> chip, I have no idea what to set it to. >>>> >>>> Unfortunately, allwinner uses GMAC which does not have any mean to detect >>>> TX FIFO Size. Default value in HW is 2k but this can not be the case in >>>> these platforms if HW team decided to change it. >>> >>> I looked at all the publicly available datasheets and Allwinner uses >>> 4K TX FIFO and 16K RX FIFO in all SoCs. Not sure if this would help. >> >> Yes, thanks for finding this! >> >> So, I think correct fix is then to hard-code these values in dwmac-sunxi.c >> probe function using the already available platform data structure. > > I guess we should also set this in the device trees, so that all DT users > can benefit. Sure, but that will be a bit harder to roll in as a bug fix. I will go ahead and submit a fix for dwmac-sunxi.c to specify a 4KB TX FIFO and 16KB RX FIFO. Thanks! -- Florian