Re: [PATCH 01/11] ACPI: update debug parameter documentation

Len Brown
2008-11-06T20:32:22Z

On Wed, 5 Nov 2008, Bjorn Helgaas wrote:

> Fix the init, debug, info level definitions, which changed recently.
>
> 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.
>
> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
> ---
> Documentation/kernel-parameters.txt | 98 ++++++++++++++++++++++-------------
> drivers/acpi/Kconfig | 12 +++-
> 2 files changed, 70 insertions(+), 40 deletions(-)
>
> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> index 1bbcaa8..ddc791e 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -198,42 +198,69 @@ 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_*= [HW,ACPI,ACPI_DEBUG]
> + CONFIG_ACPI_DEBUG must be enabled to produce any ACPI
> + debug output. The type and amount of output is
> + controlled by debug_layer and debug_level parameters,
> + which can be in decimal or hex (prefixed with "0x").
> + 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.
> +
> + To see AML "Debug" output (stores to the Debug object
> + while interpreting AML (this is enabled by default)):
> + acpi.debug_layer=0xffffffff acpi.debug_level=0x2
> + For debugging PCI/_PRT issues (PCI, info msgs):
> + acpi.debug_layer=0x400000 acpi.debug_level=0x4
> + For ACPI hardware issues (hardware, all msgs):
> + acpi.debug_layer=0x2 acpi.debug_level=0xffffffff

i like it.

> +
> + acpi.debug_layer= [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]
> + Bits in <int> correspond to _COMPONENT definitions in
> + ACPI source files. After boot, this mask can changed
> + on the fly, e.g.,
> + echo 0x2 > /sys/module/acpi/parameters/debug_layer
> + The contents of debug_layer show the names of all the
> + defined bits and their current state.
> +
> + The following are some of the global components
> + defined by the ACPI CA and the Linux OSPM:
> + 0x01 utilities
> + 0x02 hardware
> + 0x04 events
> + 0x08 tables
> + 0x10 namespace
> + 0x20 parser
> + 0x40 dispatcher
> + 0x80 executer
> + 0x100 resources
> + 0x200 ACPI CA debugger
> + 0x400 OS services
> + 0x800 ACPI CA disassembler
> + 0x40000 battery
> + 0x80000 button
> + 0x200000 fan
> + 0x400000 PCI
> + 0x10000000 bay

The (always current) bit definitions can always be had this way:

$ cat /sys/module/acpi/parameters/debug_layer
Description Hex SET
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_ALL_DRIVERS 0xFFFF0000 [*]

So I think just mentioning that is enough, rather than
reproducing it here. However, I do think that highlighting
the driver bits would be good, since they're not included above.
bay isn't a good example, as it doesn't exist any more.

I think we've got the component definitions in the wrong place.

today we have

button.c
#define ACPI_BUTTON_COMPONENT 0x00080000
#define _COMPONENT ACPI_BUTTON_COMPONENT

but this should really be

acoutput.h
#define ACPI_BUTTON_COMPONENT 0x00080000

button.c
#define _COMPONENT ACPI_BUTTON_COMPONENT

and we should print all the driver bits in the module file,
not just ACPI_ALL_DRIVERS

> +
> + Many others, e.g., ACPI_BUS_COMPONENT and
> + ACPI_AC_COMPONENT, are defined by the Linux OSPM and
> + individual drivers.
> +
> + acpi.debug_level= [HW,ACPI,ACPI_DEBUG]
> 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
> + Bits in <int> correspond to levels in ACPI_DEBUG_PRINT
> + statements. After boot, this mask can be changed on
> + the fly, e.g.,
> + echo 0x2 > /sys/module/acpi/parameters/debug_level
> + The contents of debug_level show the names of all the
> + defined bits and their current state.
> +
> + The following levels are defined by the ACPI CA:
> + 0x01 init
> + 0x02 debug (AML stores to the Debug object)
> + 0x04 info
> 0x20 init names
> 0x40 parse
> 0x80 load
> @@ -248,9 +275,6 @@ and is between 256 and 4096 characters. It is defined in the file
> 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.

actually, we have more than that:

$ cat /sys/module/acpi/parameters/debug_level
Description Hex SET
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 [ ]

>
> 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..1c954a7 100644
> --- a/drivers/acpi/Kconfig
> +++ b/drivers/acpi/Kconfig
> @@ -312,9 +312,15 @@ 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/kernel-parameters.txt to
> + control the type and amount of debug output.
> +
> + When no parameters are supplied, the default settings cause AML
> + stores to the "Debug" object to produce console output.

I think Thomas may have changed this at SuSE b/c they ship
with CONFIG_ACPI_DEBUG=y, if so, maybe upstream should also?

thanks,
-Len

->
> config ACPI_DEBUG_FUNC_TRACE
> bool "Additionally enable ACPI function tracing"
>
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