From 7a17b82ccd6671a4bb436df52eedeff906b02735 Mon Sep 17 00:00:00 2001 From: "Luis R. Rodriguez" Date: Wed, 13 Apr 2016 17:04:42 -0700 Subject: [PATCH] x86/ACPI: Parse ACPI_FADT_LEGACY_DEVICES 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 Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: andrew.cooper3@citrix.com Cc: andriy.shevchenko@linux.intel.com Cc: bigeasy@linutronix.de Cc: boris.ostrovsky@oracle.com Cc: david.vrabel@citrix.com Cc: ffainelli@freebox.fr Cc: george.dunlap@citrix.com Cc: glin@suse.com Cc: jgross@suse.com Cc: jlee@suse.com Cc: josh@joshtriplett.org Cc: julien.grall@linaro.org Cc: konrad.wilk@oracle.com Cc: kozerkov@parallels.com Cc: lenb@kernel.org Cc: lguest@lists.ozlabs.org Cc: linux-acpi@vger.kernel.org Cc: lv.zheng@intel.com Cc: matt@codeblueprint.co.uk Cc: mbizon@freebox.fr Cc: rjw@rjwysocki.net Cc: robert.moore@intel.com Cc: rusty@rustcorp.com.au Cc: tiwai@suse.de Cc: toshi.kani@hp.com Cc: xen-devel@lists.xensource.com Link: http://lkml.kernel.org/r/1460592286-300-13-git-send-email-mcgrof@kernel.org Signed-off-by: Ingo Molnar --- 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; -- 2.20.1