Re: [PATCH 2.6.26] PCI: refuse to re-add a device to a bus upon pci_scan_child_bus()

From: Matthew Wilcox
Date: Tue Jul 22 2008 - 14:11:59 EST


On Tue, Jul 22, 2008 at 08:41:00PM +0300, Eran Liberty wrote:
> >>Do you perceive any down side to my suggested patch?
> >>It seems (to me) really logical that a device can not and should not be
> >>added twice to a pci bus device list.
> >>
> >
> >The problem is the other side-effects of what you propose.
> >
> Could you elaborate what ominous side-effects you predict?

Look at the consequences of calling fixup_resource() twice on the same
resource:

res->start = (res->start + offset) & mask;
res->end = (res->end + offset) & mask;

You'll add 'offset' to the other resources twice.

--
Intel are signing my paycheques ... these opinions are still mine
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours. We can't possibly take such
a retrograde step."
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