Re: pci 0000:01:00.0: BAR 6: no parent found for of device[0xfffe0000-0xffffffff]

From: Jesse Barnes
Date: Wed Jun 24 2009 - 16:05:10 EST


On Wed, 24 Jun 2009 13:50:30 -0600
Matthew Wilcox <matthew@xxxxxx> wrote:

> On Wed, Jun 24, 2009 at 09:30:07PM +0200, Rafael J. Wysocki wrote:
> > (Adding CC to linux-pci)
>
> Thanks Rafael.
>
> > On Wednesday 24 June 2009, Justin Mattock wrote:
> > > (just pulled the latest git)
> > > And am seeing this:
> >
> > Where pci 0000:01:00.0 and 0000:02:00.0 are what?
> >
> > > [ 0.696001] pci 0000:01:00.0: BAR 6: no parent found for of
> > > device [0xfffe0000-0xffffffff]
>
> So the message is coming from pci_claim_resource, and
> if you bother to bisect, you'll track it back to my commit
> a76117dfd687ec4be0a9a05214f3009cc5f73a42 . What's going on here,
> since this is BAR 6, is we have a ROM which has been mapped high, and
> then not unmapped. The BAR doesn't fit in the parent's window, so
> the code is rightly declining to allocate the BAR.
>
> Before my patch, we silently didn't allocate the BARs. Now we print
> a message. I wonder what to do ... we could silence this warning in
> pci_claim_resource (patch below). Or we could declare this to be a
> bug, and fix it by disabling the ROM BAR (by clearing bit 0).
>
> I'm agnostic ... anyone have any preferences?

Well, given that sometimes the ROM is important, it seems like an
error. Really we should be smarter about re-allocating things as
necessary...

--
Jesse Barnes, Intel Open Source Technology Center
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