From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756509AbaAHPAt (ORCPT ); Wed, 8 Jan 2014 10:00:49 -0500 Received: from smtp.nue.novell.com ([195.135.221.5]:34962 "EHLO smtp.nue.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755224AbaAHPAp (ORCPT ); Wed, 8 Jan 2014 10:00:45 -0500 Subject: Re: [RFC PATCH 04/14] ACPI: Add ACPI 5.0 Time and Alarm Device driver From: joeyli To: "H. Peter Anvin" Cc: "Rafael J. Wysocki" , Alessandro Zummo , Matt Fleming , Matthew Garrett , Elliott@hp.com, samer.el-haj-mahmoud@hp.com, Oliver Neukum , werner@suse.com, trenn@suse.de, JBeulich@suse.com, linux-kernel@vger.kernel.org, rtc-linux@googlegroups.com, x86@kernel.org, "linux-efi@vger.kernel.org" , linux-acpi@vger.kernel.org In-Reply-To: <52CC2CDF.3000100@zytor.com> References: <1387439515-8926-1-git-send-email-jlee@suse.com> <1387439515-8926-5-git-send-email-jlee@suse.com> <52B30F43.1060306@zytor.com> <1387518099.3539.4453.camel@linux-s257.site> <52C3647B.7000708@zytor.com> <1388998707.3539.6070.camel@linux-s257.site> <52CB929C.6050403@zytor.com> <1389091244.3539.6095.camel@linux-s257.site> <52CC2CDF.3000100@zytor.com> Content-Type: text/plain; charset="UTF-8" Date: Wed, 08 Jan 2014 22:59:02 +0800 Message-ID: <1389193142.3539.6123.camel@linux-s257.site> Mime-Version: 1.0 X-Mailer: Evolution 2.28.2 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 於 二，2014-01-07 於 08:35 -0800，H. Peter Anvin 提到： > On 01/07/2014 02:40 AM, joeyli wrote: > > > > Due to accessing CMOS through ASL need enable SMM support in OVMF, > > Why? The CMOS is its own ASL address space, and you need that anyway to > be able to access the RTC proper. If you don't want to use it because > you don't want to export any indication of a legacy RTC you should be > able to just do I/O port references directly in your ASL. > > -hpa > > ACPICA denied AML access RTC ports. I tried to access 0x70, 0x71 ports in ASL on a real machine, ACPICA denied AML access to those ports. I got the following dmesg: hwvalid-0188 hw_validate_io_request: Denied AML access to port 0x0000000000000071/1 The code in acpica denied it: linux/drivers/acpi/acpica/hwvalid.c * This provides ACPICA with the desired port protections and * Microsoft compatibility. * * Description of port entries: [...] * RTC: Real-time clock * CMOS: Extended CMOS [...] */ static const struct acpi_port_info acpi_protected_ports[] = { [...] {"RTC", 0x0070, 0x0071, ACPI_OSI_WIN_XP}, {"CMOS", 0x0074, 0x0076, ACPI_OSI_WIN_XP}, Document of Windows XP: http://www.freelists.org/post/windows_errors/what-error-messages-really-mean-WinXP-IO-Ports-Blocked-from-Bios-AML-on-Windows-XP If just for ACPI TAD testing, we can remove the port protection check of RTC ports in hwvalid.c. I have read 0x70/0x71 port success after removed the checking in acpica/hwvalid.c. I will try to write RTC port in AML after remove acpica check, maybe have other unpredictable situation. Thanks a lot! Joey Lee