Messages in this thread Patch in this message | | | Subject | Re: [patch] pci: revert "PCI: remove transparent bridge sizing" | From | Benjamin Herrenschmidt <> | Date | Thu, 27 Mar 2008 10:17:41 +1100 |
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On Wed, 2008-03-26 at 22:47 +0000, Alan Cox wrote: > > I dunno. I'm not going to do anything in this area before 2.6.25 is out > > because this *does* make me a bit nervous, but if somebody wants to think > > about this and perhaps write patches for testing, that would be good. > > One way to kill off some of the assumptions and gunge would be to add > pci_resource_assigned(resource) [or indeed just resource_assigned()]. > Iomap has similar problems - we have no portable defined "not mapped" at > the moment, although we use NULL technically mmio maps of 0 end up at 0 > in the implementation today.
There is IORESOURCE_UNSET... We could use that. I use it to some extent on powerpc but x86 doesn't. Though I remember spotting a code path in setup-res.c will not clear it when actually assigning the resource to a bus. I can't remember if that hits in practice tho. I have a patch anyway :-)
---- [PATCH] pci: Make pci_assign_resource always clear IORESOURCE_UNSET
For bus resources pci_assign_resrouce() needs to also clear IORESOURCE_UNSET. (For device resources, it's handled by pci_update_resource).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> ---
Index: linux-merge/drivers/pci/setup-res.c =================================================================== --- linux-merge.orig/drivers/pci/setup-res.c 2007-12-13 13:06:27.000000000 +1100 +++ linux-merge/drivers/pci/setup-res.c 2007-12-13 13:06:50.000000000 +1100 @@ -167,7 +167,8 @@ int pci_assign_resource(struct pci_dev * (unsigned long long)res->start, pci_name(dev)); } else if (resno < PCI_BRIDGE_RESOURCES) { pci_update_resource(dev, res, resno); - } + } else + res->flags &= ~IORESOURCE_UNSET; return ret; }
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