Greg, A while back I had volunteered to write a patch that stores the resource ranges being decoded by root bridges for ACPI based i386 and x86_64 systems. The thread at: http://sourceforge.net/mailarchive/message.php?msg_id=10604487 has some context regarding this. The basic intent was to allow hot-plugged devices sitting directly under a root bridge (versus under a p2p bridge) to claim the correct resources. The current code in pci_scan_bus_parented() simply assigns ioport_resource and iomem_resource to each root bridge, even if it decodes a subset of those resources.
I did such a patch recently, and ran into problems while testing it. I made the changes in arch/i386, just like Matthew had done for arch/ia64. I found that ACPI firmware on some systems was not reporting the correct resources in the _CRS method per the ACPI specification. On other systems, there were too many resource ranges to fit in the 4 slots available in the pci_bus structure. Getting an inaccurate picture of root bridge resources broke 2 of my test systems, since some devices failed to claim resources at boot time even though they were otherwise properly configured by BIOS. I am therefore inclined to just drop this patch. This may break hotplug on systems that support hotplug slots directly connected to the root bridge. If a slot is under a p2p bridge, we already read bridge bases correctly so this problem does not affect us. Note however that I was not able to find any such i386 or x86_64 machine anyway. Does somebody have access to such a machine? Any other suggestions? Note that a similar patch went into 2.6.11-mm4'ish for ia64. I haven't heard of any breakage there, so apparently ia64 system firmware is better behaved. Rajesh - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
