ACPI: introduce module parameter acpi.aml_debug_output

Introduce module parameter acpi.aml_debug_output.

With acpi.aml_debug_output set, we can get AML debug object output
(Store (AAA, Debug)), even with CONFIG_ACPI_DEBUG cleared.

Together with the runtime custom method mechanism,
we can debug AML code problems without rebuilding the kernel.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/Documentation/acpi/method-customizing.txt b/Documentation/acpi/method-customizing.txt
index e628cd23ca8..3e1d25aee3f 100644
--- a/Documentation/acpi/method-customizing.txt
+++ b/Documentation/acpi/method-customizing.txt
@@ -19,6 +19,8 @@ Note: Only ACPI METHOD can be overridden, any other object types like
       "Device", "OperationRegion", are not recognized.
 Note: The same ACPI control method can be overridden for many times,
       and it's always the latest one that used by Linux/kernel.
+Note: To get the ACPI debug object output (Store (AAAA, Debug)),
+      please run "echo 1 > /sys/module/acpi/parameters/aml_debug_output".
 
 1. override an existing method
    a) get the ACPI table via ACPI sysfs I/F. e.g. to get the DSDT,