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Date: Thu, 9 Jun 2016 12:04:19 -0500
From: Bjorn Helgaas <helgaas@kernel.org>
To: Chen Yu <yu.c.chen@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>,
	"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
	linux-arch <linux-arch@vger.kernel.org>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Arnd Bergmann <arnd@arndb.de>,
	"Rafael J . Wysocki" <rafael@kernel.org>,
	Len Brown <lenb@kernel.org>,
	Mika Westerberg <mika.westerberg@linux.intel.com>
Subject: Re: [PATCH][RFC] PCI: Workaround to enable poweroff on Mac Pro 11
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On Thu, Jun 09, 2016 at 11:50:11AM -0500, Bjorn Helgaas wrote:

> 5) 00:1c.0 claims to have a slot that supports hotplug.  Is that
>    actually true?  Could you add a device below it?  If not, maybe the
>    problem is that the BIOS should have configured 00:1c.0 so it
>    doesn't report a slot.  If it didn't report a slot, we shouldn't
>    assign resources to it, since there is no possibility of a device
>    below it.

Of course, this would only be *part* of the problem, because a hot-added
device somewhere else could still be assigned the space at 
[mem 0x7fc00000-0x7fdfffff].

This just smells like an unreported device in there somewhere.