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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 81101C3279B for ; Mon, 2 Jul 2018 14:41:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3A56425E7D for ; Mon, 2 Jul 2018 14:41:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3A56425E7D 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-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752786AbeGBOl5 (ORCPT ); Mon, 2 Jul 2018 10:41:57 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:33636 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752040AbeGBOl4 (ORCPT ); Mon, 2 Jul 2018 10:41:56 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9269F80D; Mon, 2 Jul 2018 07:41:55 -0700 (PDT) Received: from [192.168.100.244] (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DB4073F2EA; Mon, 2 Jul 2018 07:41:54 -0700 (PDT) Subject: Re: [PATCH] ACPI/PPTT: use ACPI ID whenever ACPI_PPTT_ACPI_PROCESSOR_ID_VALID is set To: Sudeep Holla , "Rafael J. Wysocki" Cc: ACPI Devel Maling List , Linux Kernel Mailing List , Linux ARM , shunyong.yang@hxt-semitech.com, yu.zheng@hxt-semitech.com, Catalin Marinas , Will Deacon , Lorenzo Pieralisi , Andrew Jones , "Rafael J. Wysocki" References: <1530289077-2444-1-git-send-email-sudeep.holla@arm.com> <3895a0d8-9cca-2512-a06e-0ee2ac7db773@arm.com> From: Jeremy Linton Message-ID: <45daa83a-08de-24e5-c3de-35046afa33a1@arm.com> Date: Mon, 2 Jul 2018 09:41:54 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <3895a0d8-9cca-2512-a06e-0ee2ac7db773@arm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 07/02/2018 04:57 AM, Sudeep Holla wrote: > > > On 02/07/18 10:06, Rafael J. Wysocki wrote: >> On Fri, Jun 29, 2018 at 6:17 PM, Sudeep Holla wrote: >>> Currently we use the ACPI processor ID only for the leaf/processor nodes >>> as the specification states it must match the value of ACPI processor ID >>> field in the processor’s entry in the MADT. >>> >>> However, if a PPTT structure represents processors group, it match a >>> processor container UID in the namespace and ACPI_PPTT_ACPI_PROCESSOR_ID_VALID >>> flag describe whether the ACPI processor ID is valid. >>> >>> Lets use UID whenever ACPI_PPTT_ACPI_PROCESSOR_ID_VALID is set to be >>> consistent instead of using table offset as it's currently done for non >>> leaf nodes. >>> >>> Cc: "Rafael J. Wysocki" >>> Signed-off-by: Sudeep Holla >>> --- >>> drivers/acpi/pptt.c | 10 ++++++++-- >>> 1 file changed, 8 insertions(+), 2 deletions(-) >>> >>> Hi, >>> >>> There's ongoing discussion on assigning ID based in OS using simple >>> counters. It can never be consistent with firmware's view. So if the >>> firmware provides valid UID for non-processors node, we must use it. >> >> OK >> >> Do you regard this as a fix for the recently merged PPTT material? If >> so, I should apply it as a fix for 4.18. >> > > Yes, it should be considered as fix IMO. Do we know which machines are affected? I'm mostly agnostic to this patch because I believe its effectively a NOP. But that said, it could have a functional change, which implies there is some risk.