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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5F829C001B0 for ; Sun, 2 Jul 2023 08:12:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229605AbjGBIMb (ORCPT ); Sun, 2 Jul 2023 04:12:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34090 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229758AbjGBIMa (ORCPT ); Sun, 2 Jul 2023 04:12:30 -0400 Received: from mail-ed1-x52f.google.com (mail-ed1-x52f.google.com [IPv6:2a00:1450:4864:20::52f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A372410EA for ; Sun, 2 Jul 2023 01:12:28 -0700 (PDT) Received: by mail-ed1-x52f.google.com with SMTP id 4fb4d7f45d1cf-51d9128494cso3088591a12.0 for ; Sun, 02 Jul 2023 01:12:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1688285547; x=1690877547; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=AQhWpYL9hEZIUpMtAIawe0pmPnv0SY03GJaWnN0onTA=; b=xC51ZzzM4ZKoBMI4V8NMMtadmxxxemrNka3FteTPT7S80w9jo771KZxMwoCSxXnHVq mQ/Ct8hPihzooSonqa0IwxYHmKNrlItug0o22lRahVLPGJc1i55rQSPq2fN7K1quMuZm MOCR6eeodx9vxyhmr9XCuHDKgC/1DzM7KvWBbB8llOnnaM9+leerRAYvBAO6YOv0nFK0 7o46635deoSiuDR0sB0z1qogjbx3AreMLxxqTa8e11rEptZpS7koADwxBvHAhUPNcB3W ICnzlnLQ7sHXvp5fLTlxXJAhkksI+Roh13Sp/hK7eKrPoIo0ltY/2eR0NZOuHZxTm9H8 0Hew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1688285547; x=1690877547; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=AQhWpYL9hEZIUpMtAIawe0pmPnv0SY03GJaWnN0onTA=; b=bXMoavzIzk4V2ZpQteGyU0bmKggFRyVonE71HzTfAgFf4C5fjCrKARBhsyiwC2Qxqv tlu9gN/KlkW+c4wLYVNDQuAyk0GWO9Nssiksyfnr3SXuffruaghIOTLQqM1vK4haLsmj 4h269NhYQpqSB6vQxxxX5j1rTr00g25PWWJf0bWxwqSI9u7QUp/+x+VGRZmtH3A3NsuB +ZoANIYafNh3/kFejmi1c+LgQ69Mn6hQeHH+HOdvzWj2SlI5LJ1g77xJC8euT49U2bIZ 9WxGLUVX2qE0qiTH8zW/oYSKjcQarMMfBJJx42B7MinO6cMyK0cZricIajP9uE5o8MdD cumA== X-Gm-Message-State: ABy/qLZBBNDBtHuXvnyDEPPukPhdnFSuwqbKWjhJ7tCQ17B4ambJFTId 3HQSZ0lnfBCn6JQue2FEAx1uhw== X-Google-Smtp-Source: APBJJlHReryiI//h1VlOhpsruyExVn57irLSs+XOEUnGWSBEjP9I8qHbI0tF2FJsXM3COMPNyHY4aQ== X-Received: by 2002:aa7:d7c5:0:b0:51d:9664:e84 with SMTP id e5-20020aa7d7c5000000b0051d96640e84mr4610483eds.9.1688285547047; Sun, 02 Jul 2023 01:12:27 -0700 (PDT) Received: from [192.168.10.214] ([217.169.179.6]) by smtp.gmail.com with ESMTPSA id n15-20020a05640204cf00b0050bc4600d38sm8804565edw.79.2023.07.02.01.12.25 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 02 Jul 2023 01:12:26 -0700 (PDT) Message-ID: <58a26b9e-a48d-d567-c310-193a2c52521e@linaro.org> Date: Sun, 2 Jul 2023 10:12:25 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.12.0 Subject: Re: [PATCH v4 08/21] dt-bindings: reserved-memory: Add qcom,ramoops binding To: Mukesh Ojha , Rob Herring Cc: corbet@lwn.net, agross@kernel.org, andersson@kernel.org, konrad.dybcio@linaro.org, krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, keescook@chromium.org, tony.luck@intel.com, gpiccoli@igalia.com, mathieu.poirier@linaro.org, catalin.marinas@arm.com, will@kernel.org, linus.walleij@linaro.org, andy.shevchenko@gmail.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-hardening@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-gpio@vger.kernel.org References: <1687955688-20809-1-git-send-email-quic_mojha@quicinc.com> <1687955688-20809-9-git-send-email-quic_mojha@quicinc.com> Content-Language: en-US From: Krzysztof Kozlowski In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org On 28/06/2023 17:01, Mukesh Ojha wrote: > > > On 6/28/2023 8:17 PM, Rob Herring wrote: >> On Wed, Jun 28, 2023 at 6:36 AM Mukesh Ojha wrote: >>> >>> Qualcomm ramoops minidump logger provide a means of storing >>> the ramoops data to some dynamically reserved memory instead >>> of traditionally implemented ramoops where the region should >>> be statically fixed ram region. Its device tree binding >>> would be exactly same as ramoops device tree binding and is >>> going to contain traditional ramoops frontend data and this >>> content will be collected via Qualcomm minidump infrastructure >>> provided from the boot firmware. >> >> The big difference is if firmware is not deciding where this log >> lives, then it doesn't need to be in DT. How does anything except the >> kernel that allocates the log find the logs? > > Yes, you are correct, firmware is not deciding where the logs lives > instead here, Kernel has reserved the region where the ramoops region > lives and later with the minidump registration where, physical > address/size/virtual address(for parsing) are passed and that is how > firmware is able to know and dump those region before triggering system > reset. Your explanation does not justify storing all this in DT. Kernel can allocate any memory it wishes, store there logs and pass the address to the firmware. That's it, no need for DT. > > A part of this registration code you can find in 11/21 > >> I'm pretty sure I already said all this before. > > Yes, you said this before but that's the reason i came up with vendor > ramoops instead of changing traditional ramoops binding. That's unexpected conclusion. Adding more bindings is not the answer to comment that it should not be in the DTS in the first place. Best regards, Krzysztof