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[v4,12/14] x86, ACPI: parse ACPI_FADT_LEGACY_DEVICES

Message ID 1459987594-5434-13-git-send-email-mcgrof@kernel.org (mailing list archive)
State New, archived
Headers show

Commit Message

Luis Chamberlain April 7, 2016, 12:06 a.m. UTC
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@kernel.org>
---
 arch/x86/kernel/acpi/boot.c | 5 +++++
 1 file changed, 5 insertions(+)
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Patch

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 5e736e2108a1..3cada5e8505a 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -911,6 +911,11 @@  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;