Re: [PATCH 4/4] arm64: pci: acpi: Preserve PCI resources configuration when asked by ACPI

Benjamin Herrenschmidt
2019-06-21T23:07:59Z

On Fri, 2019-06-21 at 15:57 +0100, Lorenzo Pieralisi wrote:
> > pci_assign_unassigned_root_bus_resources(bus);
> >
> > list_for_each_entry(child, &bus->children, node)
>
> This is fine as far as we acknowledge that claiming resources
> on a bus is what should be done to make them immutable.

Well, as immuatable as it gets today. It's not perfect but it's a step
in the right direction. With the previous change in the series that
prevents auto-realloc when preserve_config is set, it will be
equivalent, in the current state of the code.

As part of my ongoing rework, I plan to look at making
IORESOURCE_PCI_FIXED more generally useful/robust, in which case we
could add that on top as well. That said, if we go down that path, I'm
keen on also adding a cmdline arg to ignore _DSM #5, if anything as a
test/diag tool when chasing problems caused by buggy BIOSes.

Cheers,
Ben.