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=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED 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 E282EC282C0 for ; Wed, 23 Jan 2019 22:44:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A1D8D2184C for ; Wed, 23 Jan 2019 22:44:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="kT7tlnyO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726953AbfAWWoC (ORCPT ); Wed, 23 Jan 2019 17:44:02 -0500 Received: from mail-yw1-f68.google.com ([209.85.161.68]:35699 "EHLO mail-yw1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726109AbfAWWoC (ORCPT ); Wed, 23 Jan 2019 17:44:02 -0500 Received: by mail-yw1-f68.google.com with SMTP id h32so1626620ywk.2 for ; Wed, 23 Jan 2019 14:44:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:openpgp:autocrypt:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=D5PCKuvufnyUrF8pVyMDuUHAaEbBMhhmrX8Sa9OwtWw=; b=kT7tlnyOwtXIGoSIxX0IULHsd2qb3JWBMMy+x/Dz5HcDEa/9MWMnHuBdzkf5/XXCBL sD3wiBMlII3mrOIQdTB8VnYi7kTN0lptF1nUH8lsm4UFmDrNahOZ9BYsO6576pcRkfWb CDj0XPdsZklONl9XCbwSofnczjwqr/kbmHeGdENZKcOj96/pDVuaDcxpu/Bu0TpeKfoC vL2xFmnGUx2PwqzOpfJ8HkxNu8FAlb0XX64WTk8+b3SdKr/8P43Encs+QiWOB/iIwhwg suF2oCg3Yv9FxlLHAWAvYd3gBGB++H+10YSHtAh+csEshTOr2XKsCx2jU00/HNaX1M0t NotA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:openpgp:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=D5PCKuvufnyUrF8pVyMDuUHAaEbBMhhmrX8Sa9OwtWw=; b=SN6rPNhe0xlh+Xng7NF2eipXvPws4o89zxbeF7b/GlZOpFemUEcqIzBYizWvNEjqAQ ZGnZwZbjlRPRqy7DTk8pJbHq0wglsdcCzsrbIe7V0fDuKlBVMKsY3kf9f1MCP3/LjCap Y8Hv2KVyPD7w5bUafkG1W/rxZRBge4YS82VdRpyq0yx7xZMn6qo9wLEggaI262aPK4jK +xKsZsvCS3qxhOaXJ5LCyoRV5U/QfwhrxIQ490nvwl2bIUbrbJf5uGfdbtFHdZS2tDpD 1IkHr2LYsoQ/3ucYbPqENVqN6IK8ldmbHqQIlWdBiocgvTIvIl7mBN1vAbZJGP75BFAh eiyA== X-Gm-Message-State: AJcUukcuJXp5p9lu3ZM1u5inJ/Z8Ed1yocU/m17iNhdoekS/dvzP1TEI Ece4TNBNCpXklJWL+f9eyXgb3LmV X-Google-Smtp-Source: ALg8bN7LnvvjftaAxmgr8LDzMAtLXh5A8QP1uAmGefNpTx2JdHbSfGh1gvvIMC7CBtL6959dPT8ebA== X-Received: by 2002:a81:5508:: with SMTP id j8mr3996748ywb.226.1548283440523; Wed, 23 Jan 2019 14:44:00 -0800 (PST) Received: from [10.67.49.9] ([192.19.223.250]) by smtp.googlemail.com with ESMTPSA id a15sm1623986ywh.64.2019.01.23.14.43.58 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 23 Jan 2019 14:43:59 -0800 (PST) Subject: Re: [PATCH] sfp: sfp_read: split-up request when hw rx buffer is too small. To: =?UTF-8?Q?Ren=c3=a9_van_Dorst?= , Andrew Lunn , Heiner Kallweit , "David S. Miller" , netdev@vger.kernel.org References: <20190123212046.13020-1-opensource@vdorst.com> 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, 23 Jan 2019 14:43:52 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <20190123212046.13020-1-opensource@vdorst.com> 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 1/23/19 1:20 PM, René van Dorst wrote: > Without this patch sfp code retries to read the full struct sfp_eeprom_id > id out of the SFP eeprom. Sizeof(id) is 96 bytes. > My i2c hardware, Mediatek mt7621, has a rx buffer of 64 bytes. > So sfp_read gets -NOSUPPORTED back on his turn return -EAGAIN. > Same issue is with the SFP_EXT_STATUS data which is 92 bytes. > > By split-up the request in multiple smaller requests with a max size of i2c > max_read_len, we can readout the SFP module successfully. > > Tested with MT7621 and two Fiberstore modules SFP-GB-GE-T and SFP-GE-BX. > > Signed-off-by: René van Dorst > --- > drivers/net/phy/sfp.c | 23 ++++++++++++++++++++++- > 1 file changed, 22 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c > index fd8bb998ae52..1352a19571cd 100644 > --- a/drivers/net/phy/sfp.c > +++ b/drivers/net/phy/sfp.c > @@ -367,7 +367,28 @@ static void sfp_set_state(struct sfp *sfp, unsigned int state) > > static int sfp_read(struct sfp *sfp, bool a2, u8 addr, void *buf, size_t len) > { > - return sfp->read(sfp, a2, addr, buf, len); > + const struct i2c_adapter_quirks *q = sfp->i2c->quirks; > + int ret; > + size_t rx_bytes = 0; > + > + /* Many i2c hw have limited rx buffers, split-up request when needed. */ > + while ((q->max_read_len) && (len > q->max_read_len)) { > + ret = sfp->read(sfp, a2, addr, buf, q->max_read_len); > + if (ret < 0) > + return ret; > + rx_bytes += ret; > + addr += q->max_read_len; > + buf += q->max_read_len; > + len -= q->max_read_len; > + } sfp->read defaults to sfp_i2c_read() but it is possible to override that by registering a custom sfp_bus instance (nothing does it today, but that could obviously change), so there is no guarantee that sfp->i2c->quirks is applicable unless sfp_i2c_read() is used. sfp_i2c_read() is presumably where the max_read_len splitting should occur, or better yet, should not i2c_transfer() take care of that on its own? That way there would be no layering violation of having to fetch the quirk bitmask for the i2c adapter being used, that is something that should belong in the core i2c framework. > + > + ret = sfp->read(sfp, a2, addr, buf, len); > + if (ret < 0) > + return ret; > + > + rx_bytes += ret; > + > + return rx_bytes; > } > > static int sfp_write(struct sfp *sfp, bool a2, u8 addr, void *buf, size_t len) > -- Florian