From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757319Ab3AIG2M (ORCPT ); Wed, 9 Jan 2013 01:28:12 -0500 Received: from terminus.zytor.com ([198.137.202.10]:43098 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752071Ab3AIG2K (ORCPT ); Wed, 9 Jan 2013 01:28:10 -0500 User-Agent: K-9 Mail for Android In-Reply-To: <1357712591.6113.389.camel@linux-s257.site> References: <1356712001-12198-1-git-send-email-jlee@suse.com> <1356742803.6113.245.camel@linux-s257.site> <50DE4259.7090409@zytor.com> <1357712591.6113.389.camel@linux-s257.site> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: Re: [PATCH 1/3] rtc-efi: register rtc-efi device when EFI enabled From: "H. Peter Anvin" Date: Tue, 08 Jan 2013 22:27:36 -0800 To: joeyli CC: Matthew Garrett , "matt.fleming@intel.com" , "linux-kernel@vger.kernel.org" , "linux-efi@vger.kernel.org" , Thomas Gleixner , Ingo Molnar , Jan Beulich Message-ID: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org That makes it even less compelling... joeyli wrote: >於 五，2012-12-28 於 17:07 -0800，H. Peter Anvin 提到： >> On 12/28/2012 05:00 PM, joeyli wrote: >> > 於 五，2012-12-28 於 17:43 +0000，Matthew Garrett 提到： >> >> On Sat, 2012-12-29 at 00:26 +0800, Lee, Chun-Yi wrote: >> >>> UEFI time services, GetTime(), SetTime(), GetWakeupTime(), >SetWakeupTime() are also >> >>> supported by other non-IA64 architecutre with UEFI BIOS, e.g. >x86. >> >>> >> >>> This patch changed RTC_DRV_EFI configuration to depend on EFI but >not just IA64. It >> >>> checks efi_enabled flag and efi-rtc driver should enabled. >> >> >> >> In theory, certainly - but do we still have machines that explode >if the >> >> get_time call is made? We may also want to think about disabling >the >> >> legacy access to the RTC if the EFI calls are present. >> > >> > The legacy get_time access on my test machine is work fine, not >thing >> > explode. :-) >> > Just we have a function want to expose the timezone information to >> > userspace and also store it. >> > >> >> We should indeed save the timezone information if it is available -- >> either from the ACPI TAD or from the EFI RTC, or even via some >> platform-dependent mechanism. It is important, though, that that is >> separate from the order of priority. >> >> -hpa >> > >I found Windows 8 doesn't aware/maintain the Timezone and Daylight >fields in EFI_TIME struct. > >I got a Acer UEFI notebook and I keep the Windows 8 hard drive >(/dev/sda) but install Linux to another hard drive (/dev/sdb). > >On Linux, I applied my rtc-efi patches for allow user space feed >Timezone and store it to BIOS through SetTime(). I wrote a simple user >space program to set Timezone and Daylight fields, after set those >fields I reboot to Windows 8 and use DateTime setting GUI to look at >the >change. Looks Windows doesn't aware the change, it just assume the time >in DateTime filed is local time, but didn't show the Timezone that was >set by me on Linux to GUI. > >Then, I select another Timezone(country) through Windows 8 GUI, and >reboot to Linux. I read the Timezone and Daylight by program but didn't >see the Timezone and Daylight changed by Windows 8, the value is still >the same with my latest time setting by Linux program. Windows 8 >changed >DayTime fields but didn't maintain Timezone and Daylight. > >I only have this machine with preloaded Windows 8 for verify the >behavior, not sure it's normally or not. If Windows 8 ignores Timezone >and Daylight fields in UEFI BIOS, then I think it's lower down the >necessary for we maintain Timezone and Daylight in UEFI BIOS. > >We still can store Timezone and Daylight value to UEFI, but will have >no >any interactive with Windows 8. > >Appreciate for any suggestions. > > >Thanks a lot! >Joey Lee -- Sent from my mobile phone. Please excuse brevity and lack of formatting.