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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 70DC0C433DB for ; Fri, 22 Jan 2021 08:07:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2C5F223381 for ; Fri, 22 Jan 2021 08:07:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727021AbhAVIHA (ORCPT ); Fri, 22 Jan 2021 03:07:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54114 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726777AbhAVIGm (ORCPT ); Fri, 22 Jan 2021 03:06:42 -0500 Received: from mail-wm1-x32e.google.com (mail-wm1-x32e.google.com [IPv6:2a00:1450:4864:20::32e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7A93EC06174A for ; Fri, 22 Jan 2021 00:05:57 -0800 (PST) Received: by mail-wm1-x32e.google.com with SMTP id u14so3540274wmq.4 for ; Fri, 22 Jan 2021 00:05:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=resnulli-us.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=w8/Ey9yZ3/wVzwhQAFdThnbUgWNmn6yzJJ4qmJw/2fE=; b=l5E54K8nZ70VVUK5/IiICsJH0F19c1VAckv+HLMfnqjLxkvVqOpBbacJY8g0MQpVTf MZ//LZC+b1neVK6BiB8pN5CLW51XkfsMa4cxb2QWz3wkBR4kDEfKX3rqusmhxsYB6Wjg RXQ9z1IIooh7KRxg6qI92tUa3Sj1U36MtriuzHrnR1qT57ucyClSIqzr7cBeFMILflbu iofo4/GF0r1pWU/xd2xIlsLmSxuNnt1BX543z5aoh2WEy3ZAQcrAPEB6r6n8sZpdBqLz OFsSYLhbjq+9tK0ahtB/OgNP1c4t2bpJeGeva4G+lM/GmKAlzJuK/VsVDSifdW4/wjax OGxQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=w8/Ey9yZ3/wVzwhQAFdThnbUgWNmn6yzJJ4qmJw/2fE=; b=tCpVy8bTdeKodNtxF5uskbLuDpdXOdB6pD9U/Qm6pg7G0fS5zhGM56VlAh93/Z47Vx SM8TBkoSAz/63xfia3V7Pji5FKwArk6raA2UEnoDFZPHmNju+8PXiuklMKmhbLEmDBRy xzz52wQmDXqGCXpKch68LiIFKGbuurRAyzyX/YIB9ZEMoXvV0Mfgvfu1SGWu2SQhhsiw pGgBFeF/PSR08jcrZIieGAW0Vb474KKeO32E+koxMdZh5q8aC9fzIByhO72jgvwpvhfk Q4wI5yIZjYkLUj+FPOeSKOvUTEE6riDh8C6h1Dwkddol0X2Au5Ec37W3AAQRxy9nX8pw OVKw== X-Gm-Message-State: AOAM530MxP1KiemiWAgpFKJFSydP6Jimnb969ws3SNd4b9rr4vvj8QgD AJuaaTgY4aY4xOUZLGpigUIc9A== X-Google-Smtp-Source: ABdhPJzJwDv+M2KRHTkNMPPG1a3loELuc8L3fw8dPsbNvPPrPaf82OJbai3gl5yMTPl+NnAs7giwgQ== X-Received: by 2002:a1c:9a4d:: with SMTP id c74mr2667236wme.73.1611302756311; Fri, 22 Jan 2021 00:05:56 -0800 (PST) Received: from localhost ([85.163.43.78]) by smtp.gmail.com with ESMTPSA id g132sm11225352wmg.2.2021.01.22.00.05.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 22 Jan 2021 00:05:55 -0800 (PST) Date: Fri, 22 Jan 2021 09:05:55 +0100 From: Jiri Pirko To: David Ahern Cc: Jakub Kicinski , Andrew Lunn , netdev@vger.kernel.org, davem@davemloft.net, jacob.e.keller@intel.com, roopa@nvidia.com, mlxsw@nvidia.com Subject: Re: [patch net-next RFC 00/10] introduce line card support for modular switch Message-ID: <20210122080555.GI3565223@nanopsycho.orion> References: <20210113121222.733517-1-jiri@resnulli.us> <20210119115610.GZ3565223@nanopsycho.orion> <20210120083605.GB3565223@nanopsycho.orion> <20210120154158.206b8752@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <20210121153224.GE3565223@nanopsycho.orion> <971e9eff-0b71-8ff9-d72c-aebe73cab599@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <971e9eff-0b71-8ff9-d72c-aebe73cab599@gmail.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Thu, Jan 21, 2021 at 05:38:40PM CET, dsahern@gmail.com wrote: >On 1/21/21 8:32 AM, Jiri Pirko wrote: >> Thu, Jan 21, 2021 at 12:41:58AM CET, kuba@kernel.org wrote: >>> On Wed, 20 Jan 2021 14:56:46 +0100 Andrew Lunn wrote: >>>>> No, the FW does not know. The ASIC is not physically able to get the >>>>> linecard type. Yes, it is odd, I agree. The linecard type is known to >>>>> the driver which operates on i2c. This driver takes care of power >>>>> management of the linecard, among other tasks. >>>> >>>> So what does activated actually mean for your hardware? It seems to >>>> mean something like: Some random card has been plugged in, we have no >>>> idea what, but it has power, and we have enabled the MACs as >>>> provisioned, which if you are lucky might match the hardware? >>>> >>>> The foundations of this feature seems dubious. >>> >>> But Jiri also says "The linecard type is known to the driver which >>> operates on i2c." which sounds like there is some i2c driver (in user >>> space?) which talks to the card and _does_ have the info? Maybe I'm >>> misreading it. What's the i2c driver? >> >> That is Vadim's i2c kernel driver, this is going to upstream. >> > >This pre-provisioning concept makes a fragile design to work around h/w >shortcomings. You really need a way for the management card to know Not really. As I replied to you in the other part of this thread, the linecard is basically very similar to a splitter cable. In a way, it is a splitter cable. And should be threated in a similar way. As a phy. Not as a device. Cables are replaceble without netdevice reappearing. This linecards are the same. Therefore, the concept of provisioning makes sense for them, as it does for splitter cable. >exactly what was plugged in to a slot so the control plane S/W can >respond accordingly. Surely there is a way for processes on the LC to >communicate with a process on the management card - even if it is inband >packets with special headers. If a device is capable of splitter cable/linecard hotplug, sure, that may be implemented. But the user has to configure it as such, to be aware that "cable change" may move netdevices around.