Reformat acpi.debug_layer and acpi.debug_level documentation so it's more readable, add some clues about how to figure out the mask bits that enable a specific ACPI_DEBUG_PRINT statement, and include some useful examples. Move the list of masks to Documentation/acpi/debug.txt (these are copies of the authoritative values in acoutput.h and acpi_drivers.h). Signed-off-by: Bjorn Helgaas <bjorn.helgaas@xxxxxx> --- Documentation/acpi/debug.txt | 148 +++++++++++++++++++++++++++++++++++ Documentation/kernel-parameters.txt | 75 +++++------------- drivers/acpi/Kconfig | 10 ++ 3 files changed, 178 insertions(+), 55 deletions(-) create mode 100644 Documentation/acpi/debug.txt diff --git a/Documentation/acpi/debug.txt b/Documentation/acpi/debug.txt new file mode 100644 index 0000000..65bf47c --- /dev/null +++ b/Documentation/acpi/debug.txt @@ -0,0 +1,148 @@ + 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 diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 1bbcaa8..f2ed59a 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -198,59 +198,30 @@ and is between 256 and 4096 characters. It is defined in the file that require a timer override, but don't have HPET - acpi.debug_layer= [HW,ACPI] + acpi.debug_layer= [HW,ACPI,ACPI_DEBUG] + acpi.debug_level= [HW,ACPI,ACPI_DEBUG] Format: <int> - Each bit of the <int> indicates an ACPI debug layer, - 1: enable, 0: disable. It is useful for boot time - debugging. After system has booted up, it can be set - via /sys/module/acpi/parameters/debug_layer. - CONFIG_ACPI_DEBUG must be enabled for this to produce any output. - Available bits (add the numbers together) to enable debug output - for specific parts of the ACPI subsystem: - 0x01 utilities 0x02 hardware 0x04 events 0x08 tables - 0x10 namespace 0x20 parser 0x40 dispatcher - 0x80 executer 0x100 resources 0x200 acpica debugger - 0x400 os services 0x800 acpica disassembler. - The number can be in decimal or prefixed with 0x in hex. - Warning: Many of these options can produce a lot of - output and make your system unusable. Be very careful. - - acpi.debug_level= [HW,ACPI] - Format: <int> - Each bit of the <int> indicates an ACPI debug level, - which corresponds to the level in an ACPI_DEBUG_PRINT - statement. After system has booted up, this mask - can be set via /sys/module/acpi/parameters/debug_level. - - CONFIG_ACPI_DEBUG must be enabled for this to produce - any output. The number can be in decimal or prefixed - with 0x in hex. Some of these options produce so much - output that the system is unusable. - - The following global components are defined by the - ACPI CA: - 0x01 error - 0x02 warn - 0x04 init - 0x08 debug object - 0x10 info - 0x20 init names - 0x40 parse - 0x80 load - 0x100 dispatch - 0x200 execute - 0x400 names - 0x800 operation region - 0x1000 bfield - 0x2000 tables - 0x4000 values - 0x8000 objects - 0x10000 resources - 0x20000 user requests - 0x40000 package - The number can be in decimal or prefixed with 0x in hex. - Warning: Many of these options can produce a lot of - output and make your system unusable. Be very careful. + CONFIG_ACPI_DEBUG must be enabled to produce any ACPI + debug output. Bits in debug_layer correspond to a + _COMPONENT in an ACPI source file, e.g., + #define _COMPONENT ACPI_PCI_COMPONENT + Bits in debug_level correspond to a level in + ACPI_DEBUG_PRINT statements, e.g., + ACPI_DEBUG_PRINT((ACPI_DB_INFO, ... + See Documentation/acpi/debug.txt for more information + about debug layers and levels. + + Enable AML "Debug" output, i.e., stores to the Debug + object while interpreting AML: + acpi.debug_layer=0xffffffff acpi.debug_level=0x2 + Enable PCI/PCI interrupt routing info messages: + acpi.debug_layer=0x400000 acpi.debug_level=0x4 + Enable all messages related to ACPI hardware: + acpi.debug_layer=0x2 acpi.debug_level=0xffffffff + + Some values produce so much output that the system is + unusable. The "log_buf_len" parameter may be useful + if you need to capture more output. acpi.power_nocheck= [HW,ACPI] Format: 1/0 enable/disable the check of power state. diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index f4f6329..4f75996 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -312,9 +312,13 @@ config ACPI_DEBUG bool "Debug Statements" default n help - The ACPI driver can optionally report errors with a great deal - of verbosity. Saying Y enables these statements. This will increase - your kernel size by around 50K. + The ACPI subsystem can produce debug output. Saying Y enables this + output and increases the kernel size by around 50K. + + Use the acpi.debug_layer and acpi.debug_level kernel command-line + parameters documented in Documentation/acpi/debug.txt and + Documentation/kernel-parameters.txt to control the type and + amount of debug output. config ACPI_DEBUG_FUNC_TRACE bool "Additionally enable ACPI function tracing" -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
