ACPI 5.2.9.3 IA-PC Boot Architecture flag ACPI_FADT_LEGACY_DEVICES can be used to determine if a system has legacy devices LPC or ISA devices. The x86 platform already has a struct which lists known associated legacy devices, we start off careful only by disabling root devices we should not regress with. The struct and device list can be expanded with time to cover more root legacy components. Signed-off-by: Luis R. Rodriguez <mcgrof@xxxxxxxxxx> --- arch/x86/kernel/acpi/boot.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index 8c9c2bdba092..c9a06e573fa5 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -913,6 +913,11 @@ late_initcall(hpet_insert_resource); static int __init acpi_parse_fadt(struct acpi_table_header *table) { + if (!(acpi_gbl_FADT.boot_flags & ACPI_FADT_LEGACY_DEVICES)) { + pr_debug("ACPI: no legacy devices present\n"); + x86_platform.legacy.devices.pnpbios = 0; + } + if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_CMOS_RTC) { pr_debug("ACPI: not registering RTC platform device\n"); x86_platform.legacy.rtc = 0; -- 2.7.2 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html