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(-) -- 2.9.3
