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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 726ADC28CC2 for ; Wed, 29 May 2019 15:12:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4C42523B8C for ; Wed, 29 May 2019 15:12:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726959AbfE2PMm (ORCPT ); Wed, 29 May 2019 11:12:42 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:47894 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725936AbfE2PMl (ORCPT ); Wed, 29 May 2019 11:12:41 -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 75B4B15AD; Wed, 29 May 2019 08:12:41 -0700 (PDT) Received: from [10.1.196.105] (eglon.cambridge.arm.com [10.1.196.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 63C383F5AF; Wed, 29 May 2019 08:12:40 -0700 (PDT) Subject: Re: [PATCH 11/21] EDAC, ghes: Unify trace_mc_event() code with edac_mc driver To: Robert Richter Cc: Borislav Petkov , Tony Luck , Mauro Carvalho Chehab , "linux-edac@vger.kernel.org" , "linux-kernel@vger.kernel.org" References: <20190529084344.28562-1-rrichter@marvell.com> <20190529084344.28562-12-rrichter@marvell.com> From: James Morse Message-ID: <37d47356-a40b-2739-10df-f5ab83fa2b36@arm.com> Date: Wed, 29 May 2019 16:12:38 +0100 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20190529084344.28562-12-rrichter@marvell.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Robert, On 29/05/2019 09:44, Robert Richter wrote: > Almost duplicate code, remove it. almost? > Note: there is a difference in the calculation of the grain_bits, > using the edac_mc's version here. But is it the right thing to do? Is this an off-by-one bug being papered over as some cleanup? If so could you post a separate fix that can be picked up for an rc. Do Marvell have firmware that populates this field? ... Unless the argument is no one cares about this... >From ghes_edac_report_mem_error(): | /* Error grain */ | if (mem_err->validation_bits & CPER_MEM_VALID_PA_MASK) | e->grain = ~(mem_err->physical_addr_mask & ~PAGE_MASK); Fishy, why would the kernel page-size be relevant here? If physical_addr_mask were the same as PAGE_MASK this wouldn't this always give ~0? (masking logic like this always does my head in) /me gives it ago: | {1}[Hardware Error]: physical_address: 0x00000000deadbeef | {1}[Hardware Error]: physical_address_mask: 0xffffffffffff0000 | {1}[Hardware Error]: error_type: 6, master abort | EDAC MC0: 1 CE Master abort on unknown label ( page:0xdead offset:0xbeef | grain:-1 syndrome:0x0 - status(0x0000000000000001): reserved) That 'grain:-1' is because the calculated e->grain was an unlikely 0xffffffffffffffff. Patch incoming, if you could test it on your platform that'd be great. I don't think ghes_edac.c wants this '+1'. Thanks, James