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Subject: Re: [RFC PATCH 00/14] Support timezone of ACPI TAD and EFI TIME
From: joeyli <jlee@suse.com>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Alessandro Zummo <a.zummo@towertech.it>,
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Date: Fri, 20 Dec 2013 13:38:36 +0800
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於 四，2013-12-19 於 20:22 -0800，H. Peter Anvin 提到：
> On 12/19/2013 08:05 PM, joeyli wrote:
> > 
> > Then that means the priority of PNP0B0x is higher then "CMOS RTC Not
> > Present" flag. ACPI spec doesn't have clear definition on this.
> > 
> 
> According to the Microsoft requirements documents, such a platform is
> broken and shouldn't exist.

OK~~

> 
> > I look forward to Borislav's "EFI runtime mapping" to fix the physical
> > address accessing issue of EFI time service on x86_64 machines. I tested
> > his patches on a issue machine and it works for walk around BIOS bug.
> > 
> > Can we use EFI time services on x86_64 after Borislav's patches accepted
> > to mainline?
> > 
> 
> No.
> 
> 	-hpa

If don't use EFI time, then the first priority is using ACPI TAD if it
present. Due to ACPI TAD is a generic acpi device that's need OS parsing
DSDT table before set system time.

Either move DSDT parser from subsystem initial stage to start_kernel or
move timekeeping initial to after DSDT be parsed. Which one you think is
more possible and risk less? Then I will try that way.


Thanks a lot!
Joey Lee