ACPI, APEI, EINJ Param support is disabled by default

[deliverable/linux.git] / Documentation / acpi / apei / einj.txt

diff --git a/Documentation/acpi/apei/einj.txt b/Documentation/acpi/apei/einj.txt
index dfab71848dc8f55a099beae5fa6d1a148c50c2c7..5cc699ba5453479ea13a028236f0d568063edb1e 100644 (file)
--- a/Documentation/acpi/apei/einj.txt
+++ b/Documentation/acpi/apei/einj.txt
@@ -48,12 +48,19 @@ directory apei/einj. The following files are provided.
 - param1
   This file is used to set the first error parameter value. Effect of
   parameter depends on error_type specified. For memory error, this is
-  physical memory address.
+  physical memory address.  Only available if param_extension module
+  parameter is specified.
 
 - param2
   This file is used to set the second error parameter value. Effect of
   parameter depends on error_type specified. For memory error, this is
-  physical memory address mask.
+  physical memory address mask.  Only available if param_extension
+  module parameter is specified.
+
+Injecting parameter support is a BIOS version specific extension, that
+is, it only works on some BIOS version.  If you want to use it, please
+make sure your BIOS version has the proper support and specify
+"param_extension=y" in module parameter.
 
 For more information about EINJ, please refer to ACPI specification
 version 4.0, section 17.5.