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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 7D244C54FCE for ; Wed, 25 Mar 2020 01:00:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5C0632074D for ; Wed, 25 Mar 2020 01:00:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727243AbgCYBAd (ORCPT ); Tue, 24 Mar 2020 21:00:33 -0400 Received: from mga07.intel.com ([134.134.136.100]:56575 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727113AbgCYBAd (ORCPT ); Tue, 24 Mar 2020 21:00:33 -0400 IronPort-SDR: 5F/LUuo5f3F1jXFLv4wfFvSdd2SNYFYic2tvbw088/72N7L/iWE3shXKdg3KnkiKWGo35ZxD3S UBOvwE5lpJLA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Mar 2020 18:00:32 -0700 IronPort-SDR: 10z++ObboiGRreXHC3jhskZ2nFNMkJi0JuPSu4Wk9RZgjCXbi3RKT+yPmMM9Bm6rF9cprQVSXW V54SZkuD9vww== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,302,1580803200"; d="scan'208";a="265368200" Received: from hmendezc-mobl1.amr.corp.intel.com (HELO [10.254.108.97]) ([10.254.108.97]) by orsmga002.jf.intel.com with ESMTP; 24 Mar 2020 18:00:31 -0700 Subject: Re: [PATCH v18 10/11] PCI/DPC: Add Error Disconnect Recover (EDR) support To: Bjorn Helgaas Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, ashok.raj@intel.com, Len Brown , "Rafael J. Wysocki" References: <20200324213710.GA48671@google.com> From: "Kuppuswamy, Sathyanarayanan" Message-ID: Date: Tue, 24 Mar 2020 18:00:31 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20200324213710.GA48671@google.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Bjorn, On 3/24/20 2:37 PM, Bjorn Helgaas wrote: > This is really ugly. What's the story on this firmware? It sounds > defective to me. I think there is no defined standard for this. I have checked few _DSM implementations. Some of them return default value and some don't. But atleast in the test hardware I use, we need this check. > > Or is everybody that uses _DSM supposed to check before evaluating it? I think its safer to do this check. > E.g., > > if (!acpi_check_dsm(...)) > return -EINVAL; > > obj = acpi_evaluate_dsm(...); > > If everybody is supposed to do this, it seems like the check part > should be moved into acpi_evaluate_dsm().