Re: [Regression] PCI resources allocation problem on HP nx6325

From: Linus Torvalds
Date: Tue Aug 04 2009 - 19:07:11 EST




On Mon, 3 Aug 2009, Manuel Lauss wrote:
>
> This patch introduces a warning on my system:
>
> pci 0000:02:03.0: BAR 6: address space collision on of device [0xff680000-0xff69ffff]

Heh, that's funny. I suspect you have always had the error, it's just that
back before the commit that started using "pci_claim_resource()", we did
that "find_parent_resource()+request_resource()" by hand.

So before commit a76117dfd687ec4be0a9a05214f3009cc5f73a42, the ROM
resources were done with:

pr = pci_find_parent_resource(dev, r);
if (!pr || request_resource(pr, r) < 0) {
r->end -= r->start;
r->start = 0;
}

inside pcibios_assign_resources(), and it would never warn about it, it
would just silently mark the resource unregistered (and then we'd
re-allocate it later).

So I _think_ that you actually are getting the same layout as with 2.6.30,
but with a warning that didn't exist in 2.6.30. Can you verify?

With the change to use "pci_claim_resource()", it initially changed things
to use "insert_resource()", and that shouldn't have even succeeded, but
apparently did! That's a bit scary. The patch to make it use
pci_request_resource() should have made it have the same behavior as we
had in 2.6.30 - albeit with the warning (that we didn't use to have).

I do wonder why the insert_resource() seems to have worked, though, so
maybe I'm misdiagnosing this. Can you post your /proc/iomem from 2.6.30?

Linus
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