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Date: Wed, 20 Jun 2012 21:57:28 +0200
From: Brice Goglin <brice.goglin@gmail.com>
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To: Yinghai Lu <yinghai@kernel.org>
CC: Bjorn Helgaas <bhelgaas@google.com>,
	Ulrich Drepper <drepper@gmail.com>, jbarnes@virtuousgeek.org,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
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Subject: Re: SNB PCI root information
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Le 20/06/2012 21:28, Yinghai Lu a écrit :
> On Wed, Jun 20, 2012 at 11:46 AM, Bjorn Helgaas <bhelgaas@google.com> wrote:
>
>> As far as I can tell, here's Yinghai's recommendation:  the user
>> argument should not override BIOS _PXM because if the BIOS gets the
>> _PXM wrong, the user won't be able to work around it with the
>> argument, which will force the vendor to fix the BIOS.
>>
>> I'm not buying it.  The convention that user-supplied arguments always
>> take precedence is useful, easy to document, and matches user
>> expectations.  It allows the user to work around both missing _PXM and
>> incorrect _PXM.
> if the vendor provide _PXM, that _PXM should be right and be trusted.
>

I agree that the most common problem is that _PXM is missing. But I've
seen at least some HP Westmere-EP platforms where _PXM exists but it is
wrong. Last time we checked, there was no BIOS update, even if we
reported the bug a while ago.

Brice