diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 54f21a5..7068d0b 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -258,6 +258,22 @@
 			to assume that this machine's pmtimer latches its value
 			and always returns good values.
 
+	acpi_enforce_resources=	[ACPI]
+			{ strict | lax | no }
+			Check for resource conflicts between native drivers
+			and ACPI OperationRegions (SystemIO and SystemMemory
+			only). IO ports and memory declared in ACPI might be
+			used by the ACPI subsystem in arbitrary AML code and
+			can interfere with legacy drivers.
+			strict (default): access to resources claimed by ACPI
+			is denied; legacy drivers trying to access reserved
+			resources will fail to bind to device using them.
+			lax: access to resources claimed by ACPI is allowed;
+			legacy drivers trying to access reserved resources
+			will bind successfully but a warning message is logged.
+			no: ACPI OperationRegions are not marked as reserved,
+			no further checks are performed.
+
 	agp=		[AGP]
 			{ off | try_unsupported }
 			off: disable AGP support