From mboxrd@z Thu Jan 1 00:00:00 1970 From: Huang Ying Subject: Re: [PATCH 4/8] ACPI, APEI, Resolve false conflict between ACPI NVS and APEI Date: Tue, 20 Sep 2011 10:34:12 +0800 Message-ID: <4E77FBA4.3080907@intel.com> References: <1316482741-21799-1-git-send-email-ying.huang@intel.com> <1316482741-21799-5-git-send-email-ying.huang@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mga02.intel.com ([134.134.136.20]:28866 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752190Ab1ITCeO (ORCPT ); Mon, 19 Sep 2011 22:34:14 -0400 In-Reply-To: Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Bjorn Helgaas Cc: Len Brown , "linux-kernel@vger.kernel.org" , "Luck, Tony" , "linux-acpi@vger.kernel.org" , Yinghai Lu On 09/20/2011 10:09 AM, Bjorn Helgaas wrote: > On Mon, Sep 19, 2011 at 7:38 PM, Huang Ying wrote: >> Some firmware will access memory in ACPI NVS region via APEI. That >> is, instructions in APEI ERST/EINJ table will read/write ACPI NVS >> region. The original resource conflict checking in APEI code will >> check memory/ioport accessed by APEI via general resource management >> mech. But ACPI NVS region is marked as busy already, so that the >> false resource conflict will prevent APEI ERST/EINJ to work. >> >> To fix this, this patch excludes ACPI NVS regions when APEI components >> request resources. So that they will not conflict with ACPI NVS >> regions. > > I think this is much, much too complicated. > > Yinghai's three-line e820.c patch to leave ACPI NVS regions in the > iomem_resource tree, but as not busy, is far better. ACPI NVS should only be used by firmware or firmware interpreter instead of the ordinary drivers. So I think that is reasonable to make it busy in iomem resource tree. Best Regards, Huang Ying