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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 4F3C9C43333 for ; Fri, 20 Mar 2020 12:01:17 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1C65120732 for ; Fri, 20 Mar 2020 12:01:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="AoWzGqG2" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1C65120732 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=15BYqh1L1ALv71IjF7NXoGOSeeS0sbsBf/ahe6hUVYY=; b=AoWzGqG2lL+PnT eHgf22G62sLTs4kKNimymlbuMng5lx29kBuft3E15X+B1hWZr4smk8/XlIARAMD2tVef89z6wBHTq Uj3FBiZzghCEKhiW+yJA2h/DxfBmBWBDmS2iPBQlehFOpftLMApK6uSGvHKbh4CjuYVS1FFjzli2g 10leZnncASBmeyiZl/17d3H286+dalis6nDW6GfOYMzg/zhlZJi630/CPEsmlt/4TkIr6SQYPsfpI DtjiDGeQYCZEqNvtu22etrtCleRfqtsoLyLYBSD1zn2haDJTzhhDQgoZ8+8xr2dzNR9lnhfONmyHC 8Q65eWvNSwTvJlb55XxQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jFGKy-0004HY-Gg; Fri, 20 Mar 2020 12:01:16 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jFGKt-0004Gl-QZ for linux-arm-kernel@lists.infradead.org; Fri, 20 Mar 2020 12:01:14 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7AA5D31B; Fri, 20 Mar 2020 05:01:10 -0700 (PDT) Received: from C02TD0UTHF1T.local (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1E89A3F85E; Fri, 20 Mar 2020 05:01:07 -0700 (PDT) Date: Fri, 20 Mar 2020 12:01:05 +0000 From: Mark Rutland To: Elliot Berman Subject: Re: [PATCH v3 1/3] dt: psci: Add arm,psci-sys-reset2-vendor-param property Message-ID: <20200320120105.GA36658@C02TD0UTHF1T.local> References: <1583435129-31356-1-git-send-email-eberman@codeaurora.org> <1583435129-31356-2-git-send-email-eberman@codeaurora.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1583435129-31356-2-git-send-email-eberman@codeaurora.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200320_050112_965539_E60DC8A3 X-CRM114-Status: GOOD ( 19.35 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Trilok Soni , Lorenzo Pieralisi , David Collins , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, Bjorn Andersson , Sudeep Holla , Prasad Sodagudi , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Elliot, On Thu, Mar 05, 2020 at 11:05:27AM -0800, Elliot Berman wrote: > Some implementors of PSCI may wish to use a different reset type than > SYSTEM_WARM_RESET. For instance, Qualcomm SoCs support an alternate > reset_type which may be used in more warm reboot scenarios than > SYSTEM_WARM_RESET permits (e.g. to reboot into recovery mode). To be honest, I'm still confused by this series, and I think that these patches indicate a larger problem that we cannot solve generally (e.g. on other platofrms and/or with ACPI). I think the underlying issue is whether the semantics for: a) Linux's RESET_WARM and RESET_SOFT b) PSCI's SYSTEM_RESET2 SYSTEM_WARM_RESET ... actually align in practice, which this series suggests is not the case. If those don't align, then I think that commit: 4302e381a870aafb ("firmware/psci: add support for SYSTEM_RESET2") ... is not actually reliable, and not something we can support by default, and we should rethink the code introduce in that commit. If (a) and (b) are supposed to align, and the behaviour on your platform is an erratum, then I think we should treat it as such rather than adding a property that is open to abuse. Thoughts? Thanks, Mark. > > Reviewed-by: Sudeep Holla > Signed-off-by: Elliot Berman > --- > Documentation/devicetree/bindings/arm/psci.yaml | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/Documentation/devicetree/bindings/arm/psci.yaml b/Documentation/devicetree/bindings/arm/psci.yaml > index 8ef8542..1a9d2dd 100644 > --- a/Documentation/devicetree/bindings/arm/psci.yaml > +++ b/Documentation/devicetree/bindings/arm/psci.yaml > @@ -102,6 +102,13 @@ properties: > [1] Kernel documentation - ARM idle states bindings > Documentation/devicetree/bindings/arm/idle-states.txt > > + arm,psci-sys-reset2-vendor-param: > + $ref: /schemas/types.yaml#/definitions/uint32 > + description: | > + Vendor-specific reset type parameter to use for SYSTEM_RESET2 during > + a warm or soft reboot. If no value is provided, then architectural > + reset type SYSTEM_WARM_RESET is used. > + > "#power-domain-cells": > description: > The number of cells in a PM domain specifier as per binding in [3]. > -- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > a Linux Foundation Collaborative Project _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel