This is purely a hack, for ARM64 Hyper-V guest, there is no corresponding ACPI device for the root bridge, so the best we can provide is an all-zeroed pci_config_window, and in this case make pcibios_root_bridge_prepare() act as the ACPI device is NULL. Signed-off-by: Boqun Feng <boqun.feng@xxxxxxxxx> --- arch/arm64/kernel/pci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c index e9a6eeb6a694..f159df903ccb 100644 --- a/arch/arm64/kernel/pci.c +++ b/arch/arm64/kernel/pci.c @@ -83,7 +83,7 @@ int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge) { if (!acpi_disabled) { struct pci_config_window *cfg = bridge->bus->sysdata; - struct acpi_device *adev = to_acpi_device(cfg->parent); + struct acpi_device *adev = cfg->parent ? to_acpi_device(cfg->parent) : NULL; struct device *bus_dev = &bridge->bus->dev; ACPI_COMPANION_SET(&bridge->dev, adev); -- 2.30.2