ACPI, APEI, EINJ Param support is disabled by default
EINJ parameter support is only usable for some specific BIOS.
Originally, it is expected to have no harm for BIOS does not support
it. But now, we found it will cause issue (memory overwriting) for
some BIOS. So param support is disabled by default and only enabled
when newly added module parameter named "param_extension" is
explicitly specified.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Matthew Garrett <mjg@redhat.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/Documentation/acpi/apei/einj.txt b/Documentation/acpi/apei/einj.txt
index dfab718..5cc699b 100644
--- a/Documentation/acpi/apei/einj.txt
+++ b/Documentation/acpi/apei/einj.txt
@@ -48,12 +48,19 @@
- 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.