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 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3E6A6C28CF5 for ; Wed, 26 Jan 2022 18:23:23 +0000 (UTC) Received: from localhost ([::1]:32786 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nCmx0-0003oy-0l for qemu-devel@archiver.kernel.org; Wed, 26 Jan 2022 13:23:22 -0500 Received: from eggs.gnu.org ([209.51.188.92]:53298) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nCmeH-0007Cq-7V for qemu-devel@nongnu.org; Wed, 26 Jan 2022 13:04:01 -0500 Received: from [2a00:1450:4864:20::336] (port=51016 helo=mail-wm1-x336.google.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1nCmeD-0001fF-BE for qemu-devel@nongnu.org; Wed, 26 Jan 2022 13:03:59 -0500 Received: by mail-wm1-x336.google.com with SMTP id r126so252387wma.0 for ; Wed, 26 Jan 2022 10:03:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=21tbACb1290jtk1zPwZdgD7KgkQFiOrqL1EkpKtXJPk=; b=Z83oa0bxNdElHZRS3ouXSWpwMboHgNeKu4ShewRPf1izAW153ZpWwQNiSK/dqgKlkI z5EXJIZGLMzNBhKqn5fbAZ0NvEuUYq2BGtZFkewVNMr6lr71X7p1lmkZ9f5t0y3PLZXJ f1bjsEX+0g54Ge7R8W6H7D5fmDuc5KiD+pEWSSfirGlvJTop6ghu6tDwCGFZprDo0Ge5 SLc2uNwxx5T1nzALVztQ95GSe411dFaEHm8vpCdSrDQCSb0h9zn9E8AAbC5GExu8gkfg VbfZnzhuOYmfnIN/eAiJhetsWr6+jKi6yDz0WKlw14fkFLOoe1BpPX0Dw13biI9EbNcS KjOA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=21tbACb1290jtk1zPwZdgD7KgkQFiOrqL1EkpKtXJPk=; b=8CganBG8RqZxskZs6X0OLRCfr2aZv7Ug2k/tRQJ1R+60fbphBh0D48xT3/mNyin7Vx 7+/uy9SDl+Kbw4314hHfm7JyzHHWOhlybKe1wXrAveZFMkNcrWHb7IvvnYidKsv7U8O7 xtyAXNvthA8Dap6YW4k2Zfr5jK1foT4qvJJBFNkzLD/8f6A1Fi+uuKeFmo9HFPZUhLUg vxyh3nmRkKssqr5y2n/vlhAc9DX3QxnYeHLqhhcFTwWLYZ7y2IW+cyiU8SME5QEuwkQq 9nvYEgZ9kGeC7MPRag4X+vjCM9bdKOZqT/AS02VpKFaBPM2IlrfXwSUPJ+5iA8lWbUtE HzXg== X-Gm-Message-State: AOAM532LYtdR+kO9XZib1ym6pR5nKYk7lJjdJjyB4x/rXzQ5AwsDptlR 80GeWfVf9n7XvRlZE7voJQyzwRU1MxQbZamKaf9k8g== X-Google-Smtp-Source: ABdhPJyGxKWfBmp67mA/ZyEsygTZfShkoknuh5HyYsXHLtigmomTIwc27mK9eWWyIKFInWoUIbieGBx3OZUMrp9/yvI= X-Received: by 2002:a1c:a90d:: with SMTP id s13mr95861wme.32.1643220235208; Wed, 26 Jan 2022 10:03:55 -0800 (PST) MIME-Version: 1.0 References: <20220110214755.810343-1-venture@google.com> In-Reply-To: From: Peter Maydell Date: Wed, 26 Jan 2022 18:03:44 +0000 Message-ID: Subject: Re: [PATCH 0/2] Adds designware i2c module and adds it to virt arm To: Chris Rauer Content-Type: text/plain; charset="UTF-8" X-Host-Lookup-Failed: Reverse DNS lookup failed for 2a00:1450:4864:20::336 (failed) Received-SPF: pass client-ip=2a00:1450:4864:20::336; envelope-from=peter.maydell@linaro.org; helo=mail-wm1-x336.google.com X-Spam_score_int: -12 X-Spam_score: -1.3 X-Spam_bar: - X-Spam_report: (-1.3 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, PDS_HP_HELO_NORDNS=0.001, RCVD_IN_DNSWL_NONE=-0.0001, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mst@redhat.com, Patrick Venture , qemu-devel@nongnu.org, shannon.zhaosl@gmail.com, qemu-arm@nongnu.org, ani@anisinha.ca, imammedo@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, 26 Jan 2022 at 17:12, Chris Rauer wrote: > >> I need to see a pretty strong justification for why we should be >> adding new kinds of devices to the virt machine, > > The designware i2c controller is a very common controller on many > ARM SoCs. It has device tree bindings and ACPI bindings which > makes it ideal for this platform. No, I mean, why do we need an i2c controller on the virt board at all ? > >Forgot to mention, but my prefered approach for providing > >an i2c controller on the virt board would be to have a > >PCI i2c controller: that way users who do need it can plug it > >in with a -device command line option, and users who don't > >need it never have to worry about it. > > (We seem to have an ICH9-SMB PCI device already; I have no idea if it's suitable.) > I didn't find that device suitable because it is part of the Intel > Southbridge, which may have some Intel platform quirks, and > we don't need all the things in that IO hub. That's a pity. Is there a different PCI I2C controller we could model ? thanks -- PMM