Re: [PATCHv2] PCI: QDF2432 32 bit config space accessors

From	Jon Masters <jcm@redhat.com>
Newsgroups	linux.kernel
Subject	Re: [PATCHv2] PCI: QDF2432 32 bit config space accessors
Date	2016-12-02 06:00 +0100
Message-ID	<sJO70-7cp-5@gated-at.bofh.it> (permalink)
References	(2 earlier) <sysMy-7ZA-23@gated-at.bofh.it> <syGZb-G3-13@gated-at.bofh.it> <sz6gV-8vT-13@gated-at.bofh.it> <sz6JY-gg-31@gated-at.bofh.it> <szqSl-4SQ-15@gated-at.bofh.it>
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On 11/03/2016 10:00 AM, Bjorn Helgaas wrote:

> It turns out that we can't use the _CRS of host bridges because of the
> Producer/Consumer bit screwup [1].  So the fallback is to include the
> ECAM space in the _CRS of a PNP0C02 device.  This is what the PCI
> Firmware spec r3.0, Table 4-2, footnote 2 is talking about.
> 
> Bjorn
> 
> [1] The original ACPI spec intent was that Consumer resources would be
> space like ECAM that is consumed directly by the bridge, and Producer
> resources would be the windows forwarded down to PCI.  But BIOSes
> didn't use the Producer/Consumer bit consistently, so we have to
> assume that all resources in host bridge _CRS are windows, which
> leaves us no way to describe the Consumer resources.

Aside - and now I realize you'd called this out as recently as last
month. Alas the HPE m400 I reference on the other thread about the
APM quirks doesn't have the motherboard resource entry so we're
stuck with exactly the situation you describe above there.

Jon.

-- 
Computer Architect | Sent from my Fedora powered laptop

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Re: [PATCHv2] PCI: QDF2432 32 bit config space accessors Jon Masters <jcm@redhat.com> - 2016-12-02 06:00 +0100

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