ACPI: document method tracing hooks
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/Documentation/00-INDEX b/Documentation/00-INDEX
index 299615d..161edbc 100644
--- a/Documentation/00-INDEX
+++ b/Documentation/00-INDEX
@@ -14,6 +14,7 @@
- this file.
ABI/
- info on kernel <-> userspace ABI and relative interface stability.
+
BUG-HUNTING
- brute force method of doing binary search of patches to find bug.
Changes
@@ -66,6 +67,8 @@
- how to change your VGA cursor from a blinking underscore.
accounting/
- documentation on accounting and taskstats.
+acpi/
+ - info on ACPI-specific hooks in the kernel.
aoe/
- description of AoE (ATA over Ethernet) along with config examples.
applying-patches.txt
diff --git a/Documentation/acpi/method-tracing.txt b/Documentation/acpi/method-tracing.txt
new file mode 100644
index 0000000..f6efb1e
--- /dev/null
+++ b/Documentation/acpi/method-tracing.txt
@@ -0,0 +1,26 @@
+/sys/module/acpi/parameters/:
+
+trace_method_name
+ The AML method name that the user wants to trace
+
+trace_debug_layer
+ The temporary debug_layer used when tracing the method.
+ Using 0xffffffff by default if it is 0.
+
+trace_debug_level
+ The temporary debug_level used when tracing the method.
+ Using 0x00ffffff by default if it is 0.
+
+trace_state
+ The status of the tracing feature.
+
+ "enabled" means this feature is enabled
+ and the AML method is traced every time it's executed.
+
+ "1" means this feature is enabled and the AML method
+ will only be traced during the next execution.
+
+ "disabled" means this feature is disabled.
+ Users can enable/disable this debug tracing feature by
+ "echo string > /sys/module/acpi/parameters/trace_state".
+ "string" should be one of "enable", "disable" and "1".