ACPI: Add support to parse 2nd MADT
When a BIOS bug presents multiple APIC/MADTs,
Linux currently uses the 1st and ignores the 2nd.
But some machines work better if we use the 2nd.
http://bugzilla.kernel.org/show_bug.cgi?id=7465
Add a warning and boot parameter "acpi_apic_instance=2"
to allow parsing the 2nd.
No change to default behaviour in this patch.
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 856c8b1..22c6b8c 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -138,6 +138,12 @@
See also Documentation/pm.txt, pci=noacpi
+ acpi_apic_instance= [ACPI, IOAPIC]
+ Format: <int>
+ 2: use 2nd APIC table, if available
+ 1,0: use 1st APIC table
+ default: 0
+
acpi_sleep= [HW,ACPI] Sleep options
Format: { s3_bios, s3_mode }
See Documentation/power/video.txt
