 a0d84a92df
			
		
	
	
	a0d84a92df
	
	
	
		
			
			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@hp.com> Signed-off-by: Len Brown <len.brown@intel.com>
		
			
				
	
	
		
			148 lines
		
	
	
	
		
			5.6 KiB
			
		
	
	
	
		
			Text
		
	
	
	
	
	
			
		
		
	
	
			148 lines
		
	
	
	
		
			5.6 KiB
			
		
	
	
	
		
			Text
		
	
	
	
	
	
| 			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
 |