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=-14.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,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 39035C4361B for ; Fri, 18 Dec 2020 21:09:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DA20923B88 for ; Fri, 18 Dec 2020 21:09:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727791AbgLRVJs (ORCPT ); Fri, 18 Dec 2020 16:09:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36794 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725966AbgLRVJr (ORCPT ); Fri, 18 Dec 2020 16:09:47 -0500 Received: from mail-pj1-x1029.google.com (mail-pj1-x1029.google.com [IPv6:2607:f8b0:4864:20::1029]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 450C5C0617A7; Fri, 18 Dec 2020 13:09:07 -0800 (PST) Received: by mail-pj1-x1029.google.com with SMTP id iq13so1972419pjb.3; Fri, 18 Dec 2020 13:09:07 -0800 (PST) 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=K35ORGewLjqPw1uKHr7bYXsr1cXEc+og2jhf6OchoDg=; b=PRaW34VUYpfZebEdOPLfMdNEiQrP/uQ290Wq4iC+/DgfEEh9XFXow/B19zkI0dotmM /hY2LWc/KcfA6ji2BTui3OUQeNNRYfwfWcK0hsRXmepRm1+ySGBe2dC0WDr6AxBX1Xoz vhuoDXT+oAL9oc8K8gLFsZ04vgLRmg7pHNin1CO7Ii1wUBYrNDcB1n+5dRY36MbnULND nmFoQv0mrBPQsaq8sF2YjvDCpIRyBjA12vFYif7IJWigqdvB8d/WiOHWHCigA4RQdhsr 6LUzXk/Z9T37pq56WJs1jNiZu+5Wr1s+/NwF+enzz7DjC/SmZCQzdcRiiXVoCKjsmw4F D01w== 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=K35ORGewLjqPw1uKHr7bYXsr1cXEc+og2jhf6OchoDg=; b=c02tX8BIqLKgCX5cS1FVmcc/gL0sODAEtNcoQ2fTSVC+nVDqU6Ur4L/ZV9c2hz1bLe UUU4i+Yk8Zod1q7c553Q2RJVwa78JX8cP1zvMuDZaMSVBw1JJRrJxqA2RIy0Y8hGjq+z N2MRhXvdz9EGjvwpHqRq5MlD+ZQhA2lWctSr+oHj4xYXWXrgnzX10RfmgwSzjieCq5n9 z50q/eNMU6+k+rofE0vmRLqQ7dW+2bCRU9UClwvbbaftGtEgawCLImlZbFLD97l2B5uz zDGC/uZX+Qlx3Mv+XUYxuc8P1L3wDFFz6muIKsqRL8QQBvArhNNzENCUssxBBjVOFLt7 3P6A== X-Gm-Message-State: AOAM532AZkE0EGSaaPRUezyNVoBYLRwPabUWGzC9VHF99dg5n5AhpLaz t+nYH00yQJuh81EdLea8miwQVx26l08= X-Google-Smtp-Source: ABdhPJwE8VQFjnqvWEJlvhODaPPsfA0AFCXodNGgUM6e7hMBqrebr4ESRwIMRlw7eIEpkoCV/AjidA== X-Received: by 2002:a17:90b:1c10:: with SMTP id oc16mr6023416pjb.144.1608325746394; Fri, 18 Dec 2020 13:09:06 -0800 (PST) Received: from [10.67.48.230] ([192.19.223.252]) by smtp.googlemail.com with ESMTPSA id 3sm9493099pfv.92.2020.12.18.13.09.00 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 18 Dec 2020 13:09:05 -0800 (PST) Subject: Re: [PATCH net] net: systemport: set dev->max_mtu to UMAC_MAX_MTU_SIZE To: Vladimir Oltean , Florian Fainelli Cc: netdev@vger.kernel.org, andrew@lunn.ch, "David S. Miller" , Jakub Kicinski , Murali Krishna Policharla , Vladimir Oltean , "open list:BROADCOM SYSTEMPORT ETHERNET DRIVER" , open list References: <20201218173843.141046-1-f.fainelli@gmail.com> <20201218202441.ppcxswvlix3xszsn@skbuf> <20201218205220.jb3kh7v23gtpymmx@skbuf> <20201218210250.owahylqnagtssbsw@skbuf> From: Florian Fainelli 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: Fri, 18 Dec 2020 13:08:58 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201218210250.owahylqnagtssbsw@skbuf> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/18/20 1:02 PM, Vladimir Oltean wrote: > On Fri, Dec 18, 2020 at 12:54:33PM -0800, Florian Fainelli wrote: >> On 12/18/20 12:52 PM, Vladimir Oltean wrote: >>> On Fri, Dec 18, 2020 at 12:30:20PM -0800, Florian Fainelli wrote: >>>> On 12/18/20 12:24 PM, Vladimir Oltean wrote: >>>>> Hi Florian, >>>>> >>>>> On Fri, Dec 18, 2020 at 09:38:43AM -0800, Florian Fainelli wrote: >>>>>> The driver is already allocating receive buffers of 2KiB and the >>>>>> Ethernet MAC is configured to accept frames up to UMAC_MAX_MTU_SIZE. >>>>>> >>>>>> Fixes: bfcb813203e6 ("net: dsa: configure the MTU for switch ports") >>>>>> Signed-off-by: Florian Fainelli >>>>>> --- >>>>>> drivers/net/ethernet/broadcom/bcmsysport.c | 1 + >>>>>> 1 file changed, 1 insertion(+) >>>>>> >>>>>> diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c >>>>>> index 0fdd19d99d99..b1ae9eb8f247 100644 >>>>>> --- a/drivers/net/ethernet/broadcom/bcmsysport.c >>>>>> +++ b/drivers/net/ethernet/broadcom/bcmsysport.c >>>>>> @@ -2577,6 +2577,7 @@ static int bcm_sysport_probe(struct platform_device *pdev) >>>>>> NETIF_F_HW_VLAN_CTAG_TX; >>>>>> dev->hw_features |= dev->features; >>>>>> dev->vlan_features |= dev->features; >>>>>> + dev->max_mtu = UMAC_MAX_MTU_SIZE; >>>>>> >>>>>> /* Request the WOL interrupt and advertise suspend if available */ >>>>>> priv->wol_irq_disabled = 1; >>>>>> -- >>>>>> 2.25.1 >>>>>> >>>>> >>>>> Do you want to treat the SYSTEMPORT Lite differently? >>>>> >>>>> /* Set maximum frame length */ >>>>> if (!priv->is_lite) >>>>> umac_writel(priv, UMAC_MAX_MTU_SIZE, UMAC_MAX_FRAME_LEN); >>>>> else >>>>> gib_set_pad_extension(priv); >>>> >>>> SYSTEMPORT Lite does not actually validate the frame length, so setting >>>> a maximum number to the buffer size we allocate could work, but I don't >>>> see a reason to differentiate the two types of MACs here. >>> >>> And if the Lite doesn't validate the frame length, then shouldn't it >>> report a max_mtu equal to the max_mtu of the attached DSA switch, plus >>> the Broadcom tag length? Doesn't the b53 driver support jumbo frames? >> >> And how would I do that without create a horrible layering violation in >> either the systemport driver or DSA? Yes the b53 driver supports jumbo >> frames. > > Sorry, I don't understand where is the layering violation (maybe it doesn't > help me either that I'm not familiar with Broadcom architectures). > > Is the SYSTEMPORT Lite always used as a DSA master, or could it also be > used standalone? What would be the issue with hardcoding a max_mtu value > which is large enough for b53 to use jumbo frames? SYSTEMPORT Lite is always used as a DSA master AFAICT given its GMII Integration Block (GIB) was specifically designed with another MAC and particularly that of a switch on the other side. The layering violation I am concerned with is that we do not know ahead of time which b53 switch we are going to be interfaced with, and they have various limitations on the sizes they support. Right now b53 only concerns itself with returning JMS_MAX_SIZE, but I am fairly positive this needs fixing given the existing switches supported by the driver. -- Florian