On Thursday 31 January 2008 05:50:13 pm Linus Torvalds wrote:
On Thu, 31 Jan 2008, Robert Hancock wrote:
I think so. There was one objection that it introduced a dependency on pnpacpi loading after PCI bus enumeration, though.
Linus also suggested that pnpacpi could be marking the resources as "present but unused" so that drivers can request those regions but we still prevent dynamically assigning resources into them.
I _think_ that's what ACPI used to do before switching over to the PnPACPI thing, so I do think that "present but not reserved" approach is not just the right one, but also the (historically) tested one.
The reservation happens in drivers/pnp/system.c, and it does mark the region as "not busy."
I think the problem here is that the PCI BAR is bigger and spans the region reported by ACPI:
[ 22.906654] system 00:08: iomem range 0xfebfa000-0xfebfac00 has been reserved [ 31.133141] PCI: Unable to reserve mem region #1:4000@febf8000 for device 0000:00:1b.0
We can easily add more BIOSes to the PNP quirk.
I really don't want to use the earlier quirk that scanned PCI devices from a PNP quirk. I think that's just wrong because PNP (which conceptually includes ACPI) is what tells us about PCI root bridges.
Bjorn