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authorLinus Torvalds <torvalds@linux-foundation.org>2019-05-07 05:35:13 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-05-07 05:35:13 +0300
commit59df1c2bdecb0d1aaadfb8533df4bea528ee4952 (patch)
treeded1e05c84622331dd6a61b24db31e9b920f6970 /Documentation/firmware-guide/acpi/debug.rst
parentc620f7bd0ba5c882b3e7fc199a8d5c2f6c2f5263 (diff)
parent10b4768b27a0b8f9459570723ecb1809f4d707e0 (diff)
downloadlinux-59df1c2bdecb0d1aaadfb8533df4bea528ee4952.tar.xz
Merge tag 'acpi-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI updates from Rafael Wysocki: "These rearrange the ACPI documentation by converting it to the .rst format and splitting it into clear categories (admin guide, driver API, firmware guide), switch over multiple users of a problematic library function to a new better one, update the ACPICA code in the kernel to a new upstream release, fix a few issues, improve power device management diagnostics and do some cleanups. Specifics: - Convert the ACPI documentation in the kernel source tree to the .rst format and split it into the admin guide, driver API and firmware guide parts (Changbin Du). - Add a PRP0001 usage example to the ACPI documentation (Thomas Preston). - Switch over the users of the acpi_dev_get_first_match_name() library function which turned out to be problematic to a new, better one called acpi_dev_get_first_match_dev() (Andy Shevchenko, YueHaibing). - Update the ACPICA code in the kernel to upstream release 20190405 including: * Null pointer dereference check in acpi_ns_delete_node() (Erik Schmauss). * Multiple macro and function name changes (Bob Moore). * Predefined operation region name fix (Erik Schmauss). - Fix hibernation issue on systems using the Baytrail and Cherrytrail Intel SoCs introduced during the 4.20 development cycle (Hans de Goede). - Add Sony VPCEH3U1E to the backlight quirk list (Zhang Rui). - Fix button handling during system resume (Zhang Rui). - Add a device PM diagnostic message (Rafael Wysocki). - Clean up the code, comments and white space in multiple places (Bjorn Helgaas, Gustavo Silva, Kefeng Wang)" * tag 'acpi-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (53 commits) Documentation: ACPI: move video_extension.txt to firmware-guide/acpi and convert to reST Documentation: ACPI: move ssdt-overlays.txt to admin-guide/acpi and convert to reST Documentation: ACPI: move lpit.txt to firmware-guide/acpi and convert to reST Documentation: ACPI: move cppc_sysfs.txt to admin-guide/acpi and convert to reST Documentation: ACPI: move apei/einj.txt to firmware-guide/acpi and convert to reST Documentation: ACPI: move apei/output_format.txt to firmware-guide/acpi and convert to reST Documentation: ACPI: move aml-debugger.txt to firmware-guide/acpi and convert to reST Documentation: ACPI: move method-tracing.txt to firmware-guide/acpi and convert to rsST Documentation: ACPI: move debug.txt to firmware-guide/acpi and convert to reST Documentation: ACPI: move dsd/data-node-references.txt to firmware-guide/acpi and convert to reST Documentation: ACPI: move dsd/graph.txt to firmware-guide/acpi and convert to reST Documentation: ACPI: move acpi-lid.txt to firmware-guide/acpi and convert to reST Documentation: ACPI: move i2c-muxes.txt to firmware-guide/acpi and convert to reST Documentation: ACPI: move dsdt-override.txt to admin-guide/acpi and convert to reST Documentation: ACPI: move initrd_table_override.txt to admin-guide/acpi and convert to reST Documentation: ACPI: move method-customizing.txt to firmware-guide/acpi and convert to reST Documentation: ACPI: move gpio-properties.txt to firmware-guide/acpi and convert to reST Documentation: ACPI: move DSD-properties-rules.txt to firmware-guide/acpi and covert to reST Documentation: ACPI: move scan_handlers.txt to driver-api/acpi and convert to reST Documentation: ACPI: move linuxized-acpica.txt to driver-api/acpi and convert to reST ...
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+.. SPDX-License-Identifier: GPL-2.0
+
+=================
+ACPI Debug Output
+=================
+
+The ACPI CA, the Linux ACPI core, and some ACPI drivers can generate debug
+output. This document describes how to use this facility.
+
+Compile-time configuration
+==========================
+
+ACPI debug output is globally enabled by CONFIG_ACPI_DEBUG. If this config
+option is turned off, the debug messages are not even built into the
+kernel.
+
+Boot- and run-time configuration
+================================
+
+When CONFIG_ACPI_DEBUG=y, you can select the component and level of messages
+you're interested in. At boot-time, use the acpi.debug_layer and
+acpi.debug_level kernel command line options. After boot, you can use the
+debug_layer and debug_level files in /sys/module/acpi/parameters/ to control
+the debug messages.
+
+debug_layer (component)
+=======================
+
+The "debug_layer" is a mask that selects components of interest, e.g., a
+specific driver or part of the ACPI interpreter. To build the debug_layer
+bitmask, look for the "#define _COMPONENT" in an ACPI source file.
+
+You can set the debug_layer mask at boot-time using the acpi.debug_layer
+command line argument, and you can change it after boot by writing values
+to /sys/module/acpi/parameters/debug_layer.
+
+The possible components are defined in include/acpi/acoutput.h and
+include/acpi/acpi_drivers.h. Reading /sys/module/acpi/parameters/debug_layer
+shows the supported mask values, currently these::
+
+ ACPI_UTILITIES 0x00000001
+ ACPI_HARDWARE 0x00000002
+ ACPI_EVENTS 0x00000004
+ ACPI_TABLES 0x00000008
+ ACPI_NAMESPACE 0x00000010
+ ACPI_PARSER 0x00000020
+ ACPI_DISPATCHER 0x00000040
+ ACPI_EXECUTER 0x00000080
+ ACPI_RESOURCES 0x00000100
+ ACPI_CA_DEBUGGER 0x00000200
+ ACPI_OS_SERVICES 0x00000400
+ ACPI_CA_DISASSEMBLER 0x00000800
+ ACPI_COMPILER 0x00001000
+ ACPI_TOOLS 0x00002000
+ ACPI_BUS_COMPONENT 0x00010000
+ ACPI_AC_COMPONENT 0x00020000
+ ACPI_BATTERY_COMPONENT 0x00040000
+ ACPI_BUTTON_COMPONENT 0x00080000
+ ACPI_SBS_COMPONENT 0x00100000
+ ACPI_FAN_COMPONENT 0x00200000
+ ACPI_PCI_COMPONENT 0x00400000
+ ACPI_POWER_COMPONENT 0x00800000
+ ACPI_CONTAINER_COMPONENT 0x01000000
+ ACPI_SYSTEM_COMPONENT 0x02000000
+ ACPI_THERMAL_COMPONENT 0x04000000
+ ACPI_MEMORY_DEVICE_COMPONENT 0x08000000
+ ACPI_VIDEO_COMPONENT 0x10000000
+ ACPI_PROCESSOR_COMPONENT 0x20000000
+
+debug_level
+===========
+
+The "debug_level" is a mask that selects different types of messages, e.g.,
+those related to initialization, method execution, informational messages, etc.
+To build debug_level, look at the level specified in an ACPI_DEBUG_PRINT()
+statement.
+
+The ACPI interpreter uses several different levels, but the Linux
+ACPI core and ACPI drivers generally only use ACPI_LV_INFO.
+
+You can set the debug_level mask at boot-time using the acpi.debug_level
+command line argument, and you can change it after boot by writing values
+to /sys/module/acpi/parameters/debug_level.
+
+The possible levels are defined in include/acpi/acoutput.h. Reading
+/sys/module/acpi/parameters/debug_level shows the supported mask values,
+currently these::
+
+ ACPI_LV_INIT 0x00000001
+ ACPI_LV_DEBUG_OBJECT 0x00000002
+ ACPI_LV_INFO 0x00000004
+ ACPI_LV_INIT_NAMES 0x00000020
+ ACPI_LV_PARSE 0x00000040
+ ACPI_LV_LOAD 0x00000080
+ ACPI_LV_DISPATCH 0x00000100
+ ACPI_LV_EXEC 0x00000200
+ ACPI_LV_NAMES 0x00000400
+ ACPI_LV_OPREGION 0x00000800
+ ACPI_LV_BFIELD 0x00001000
+ ACPI_LV_TABLES 0x00002000
+ ACPI_LV_VALUES 0x00004000
+ ACPI_LV_OBJECTS 0x00008000
+ ACPI_LV_RESOURCES 0x00010000
+ ACPI_LV_USER_REQUESTS 0x00020000
+ ACPI_LV_PACKAGE 0x00040000
+ ACPI_LV_ALLOCATIONS 0x00100000
+ ACPI_LV_FUNCTIONS 0x00200000
+ ACPI_LV_OPTIMIZATIONS 0x00400000
+ ACPI_LV_MUTEX 0x01000000
+ ACPI_LV_THREADS 0x02000000
+ ACPI_LV_IO 0x04000000
+ ACPI_LV_INTERRUPTS 0x08000000
+ ACPI_LV_AML_DISASSEMBLE 0x10000000
+ ACPI_LV_VERBOSE_INFO 0x20000000
+ ACPI_LV_FULL_TABLES 0x40000000
+ ACPI_LV_EVENTS 0x80000000
+
+Examples
+========
+
+For example, drivers/acpi/bus.c contains this::
+
+ #define _COMPONENT ACPI_BUS_COMPONENT
+ ...
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device insertion detected\n"));
+
+To turn on this message, set the ACPI_BUS_COMPONENT bit in acpi.debug_layer
+and the ACPI_LV_INFO bit in acpi.debug_level. (The ACPI_DEBUG_PRINT
+statement uses ACPI_DB_INFO, which is macro based on the ACPI_LV_INFO
+definition.)
+
+Enable all AML "Debug" output (stores to the Debug object while interpreting
+AML) during boot::
+
+ acpi.debug_layer=0xffffffff acpi.debug_level=0x2
+
+Enable PCI and PCI interrupt routing debug messages::
+
+ acpi.debug_layer=0x400000 acpi.debug_level=0x4
+
+Enable all ACPI hardware-related messages::
+
+ acpi.debug_layer=0x2 acpi.debug_level=0xffffffff
+
+Enable all ACPI_DB_INFO messages after boot::
+
+ # echo 0x4 > /sys/module/acpi/parameters/debug_level
+
+Show all valid component values::
+
+ # cat /sys/module/acpi/parameters/debug_layer