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Message-ID: <54FFF408.1000703@linux.intel.com>
Date: Wed, 11 Mar 2015 15:51:36 +0800
From: "Li, Aubrey" <aubrey.li@linux.intel.com>
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To: Ingo Molnar <mingo@kernel.org>
CC: Ingo Molnar <mingo@redhat.com>,
        "alan@linux.intel.com" <alan@linux.intel.com>,
        Arjan van de Ven <arjan@linux.intel.com>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        "Brown, Len" <len.brown@intel.com>,
        "H. Peter Anvin" <hpa@linux.intel.com>, x86@kernel.org,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] x86: Bypass legacy PIC and PIT in ACPI hardware reduced
 mode
References: <54FFC593.6070002@linux.intel.com> <20150311062324.GA29788@gmail.com>
In-Reply-To: <20150311062324.GA29788@gmail.com>
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On 2015/3/11 14:23, Ingo Molnar wrote:
> 
> * Li, Aubrey <aubrey.li@linux.intel.com> wrote:
> 
>> On a platform in ACPI Hardware-reduced mode, the legacy PIC and PIT
>> may not be initialized even though they may be present in silicon.
>> Touching these legacy components causes unexpected result on system.
> 
> s/causes unexpected result on system/
>   causes unexpected results on the system
> 
>>
>> On Bay Trail-T(ASUS-T100) platform, touching these legacy components
> 
> s/On Bay Trail-T(ASUS-T100) platform/
>   On the Bay Trail-T(ASUS-T100) platform
> 
> Ok, my final bike shed painting job would be to move the 
> 'acpi_gbl_reduced_hardware' flag check inside acpi_reduced_hw_init(): 
> that makes it nicely self-sustained and all in a single place.
> 
> With that fixed it looks good to me.

Thanks, I'll cook v3 soon, :-)
> 
> Should I merge it for v4.0 upstream merge, in tip:x86/urgent?
> 
> The 'touches hardware in unexpected ways' aspect qualifies it for 
> urgent treatment IMO.

Currently the unexpected result is that it blocks a low power idle
during suspend. I'm not sure if it can be for x86/urgent. But it would
be nice if it can be a bug-fix in v4.0.

Thanks,
-Aubrey

> 
> Thanks,
> 
> 	Ingo
> 
>