From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-x232.google.com (mail-io0-x232.google.com [IPv6:2607:f8b0:4001:c06::232]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3w7XG639s5zDq5W for ; Thu, 20 Apr 2017 05:32:45 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.b="Beww017X"; dkim-atps=neutral Received: by mail-io0-x232.google.com with SMTP id o22so36133537iod.3 for ; Wed, 19 Apr 2017 12:32:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=qJUdj1XoI2T04y8+T9+QbjTK5f1t0GylWCnlYHJOo0w=; b=Beww017XwPGncWr79ophrSb6k2xa/91gMrBuJx38D5+dyHryWCowjUiOtkYhP/QO1r os5hQ6YVuxrTegxyQOkY98VlMl079lwhysHH1HniBCX/wyfSpQ8HlDugeE6mzhbBJlhT 9cwM19HTnkh9tpzvdz4FguqjCp7CHVTgMjSmN5fo4t7Fd49mor4REBxhzjwERNjPeJer kyoPiA76NAsJAxIRJTxovjx9mkLMcjW+TALhxtMRQUgTkiuCq4p34/Ana4w+g9XTm60U 0FwAzsklopp9+5fFnOk7d6RioQmhAW2YTdCZYqKR+1Wj2DwpAGBtTJJWzekAev8BQPNY CEJw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=qJUdj1XoI2T04y8+T9+QbjTK5f1t0GylWCnlYHJOo0w=; b=pVDUON8YTba+KOP/UD83jdy6zmi9ENa3+U/Cma+9N6vUdW5NeIYVD6Br9re/0nqcVe fxFC0xRzy+Or8nPCMe7qlJcEbtA79liA/fHL2SlQgQ8u6Js4OvU8GaY3w5AiS+7TFkVO nme9bs5BAAgXfPKX7erMOuJl7iXQW1n3zM/H4gS4en4RW4GbOs6BCbk4X44ad+1850C7 /Gooeh2Fx7y9MPVc3IWPM2A/tU6SeDW+c4Q2cJQVYVdq6XocNDGWu4AmuoIIUAfZ/vlR 6DPJbFCHUU08L8r0dc/Pvekfhlbu9RmArtMCUxPWpRijAhFBjv+7LS+bOz0n5qLRlza8 MapA== X-Gm-Message-State: AN3rC/7ncDHj4c22wgIG3058uz1QD/AFRH147JkClZm0EwbItxaNlm11 VfA0VSemdQGJTqwVMy2xnSjrjIcVmhnm X-Received: by 10.107.26.17 with SMTP id a17mr5216513ioa.72.1492630363507; Wed, 19 Apr 2017 12:32:43 -0700 (PDT) MIME-Version: 1.0 Received: by 10.36.84.202 with HTTP; Wed, 19 Apr 2017 12:32:42 -0700 (PDT) In-Reply-To: <11221492599488@webcorp01f.yandex-team.ru> References: <58EE852E.8010005@linux.vnet.ibm.com> <214891492421512@webcorp03h.yandex-team.ru> <11221492599488@webcorp01f.yandex-team.ru> From: Peter Hanson Date: Wed, 19 Apr 2017 12:32:42 -0700 Message-ID: Subject: Re: Plans for BMC i2c to host bridge via IPMI To: "Anton D. Kachalov" Cc: Chris Austen , tomjose , OpenBMC Maillist Content-Type: text/plain; charset=UTF-8 X-BeenThere: openbmc@lists.ozlabs.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Development list for OpenBMC List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 19 Apr 2017 19:32:47 -0000 Anton, Thank you for the interesting contributions. As noted earlier, the Master send-receive message is inadequate to describe the private bus array in a modern Bmc. And has other senseless limitations. But using another message seems like a small difference. So I have been studying your design for its key ideas. I have some basic high-level questions and/or guesses. A higher level entity sends messages to one `adapter', which then sends them to i2c. More-or-less separately, a slave adapter receives replies and converts them back to messages to that entity. I now think ipmid can act as that entity. If so, it would be useful to understand completely how that works. I see what looks like usable slave I2C adapter code. Is it for multimaster I2C bus? Or do infernal messaging flows also use it? Thanks again, -- peterh