firmware-guide/acpi/method-tracing.rst

15 method tracing facility.
20 ACPICA provides method tracing capability. And two functions are
33 But when the particular layer/level is applied to the control method
37 logs when the control method evaluation is started, and disable the
38 detailed logging when the control method evaluation is stopped.
52    control method is being evaluated::
58       # echo "method" > /sys/module/acpi/parameters/trace_state
61    control method is being evaluated for the first time::
67       # echo "method-once" > /sys/module/acpi/parameters/trace_state
74      Full path of a control method that can be found in the ACPI namespace.
75      It needn't be an entry of a control method evaluation.
80 There are special log entries added by the method tracing facility at
82 method, or an AML opcode. Note that the format of the log entries are
109 a. Filter out the method start/stop "AML tracer" logs when control
117 b. Filter out the method start/stop "AML tracer" when the specified
118    control method is being evaluated::
124       # echo "method" > trace_state
126 c. Filter out the method start/stop "AML tracer" logs when the specified
127    control method is being evaluated for the first time::
133       # echo "method-once" > trace_state
135 d. Filter out the method/opcode start/stop "AML tracer" when the
136    specified control method is being evaluated::
144 e. Filter out the method/opcode start/stop "AML tracer" when the
145    specified control method is being evaluated for the first time::
153 Note that all above method tracing facility related module parameters can
163 All method tracing functions can be configured via ACPI module
167   The full path of the AML method that the user wants to trace.
195   Disable the method tracing feature.
198   Enable the method tracing feature.
201   during any method execution will be logged.
203 "method"
204   Enable the method tracing feature.
207   during method execution of "trace_method_name" will be logged.
209 "method-once"
210   Enable the method tracing feature.
213   during method execution of "trace_method_name" will be logged only once.
216   Enable the method tracing feature.
219   during method/opcode execution of "trace_method_name" will be logged.
222   Enable the method tracing feature.
225   during method/opcode execution of "trace_method_name" will be logged only
233    method evaluations, after configuring "trace_state" to "enable",
235 2. When "method/opcode" is specified, if
238    apply to all control method evaluations.