[PATCH 0/2] arm64: acpi/pci: allow the firmware BAR configuration to be preserved

[Bjorn Helgaas]

On Tue, Apr 11, 2017 at 05:33:11PM +0100, Ard Biesheuvel wrote:
> This is a followup to the discussion regarding whether ACPI/arm64 systems
> should preserve the PCI configuration performed by the firmware, or always
> reconfigure it from scratch.
> 
> This series proposes to put it under the control of the firmware, by invoking
> the _DSM method, and preserving the firmware configuration only when it
> returns 0.
> 
> Patch #1 is a preparatory bugfix that solves the issue that I/O bridge
> windows starting at 0x0 are dismissed when looking for parent resources.
> 
> Patch #2 adds the logic to invoke the _DSM and claim the existing
> configuration rather than reallocate it from scratch if it returns '0'
> 
> Ard Biesheuvel (2):
>   drivers: pci: do not disregard parent resources starting at 0x0
>   arm64: acpi/pci: invoke _DSM whether to preserve firmware PCI setup
> 
>  arch/arm64/kernel/pci.c  | 20 ++++++++++++++++++--
>  drivers/pci/pci.c        |  2 +-
>  include/linux/pci-acpi.h |  7 ++++---
>  3 files changed, 23 insertions(+), 6 deletions(-)

I applied the first to pci/resource for v4.13.  I didn't do anything
with the second because I don't think we have consensus on what the
right thing to do is yet.