ACPI: update debug parameter documentation

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>

1 files changed, 23 insertions, 52 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 343e0f0f84b6..e8951118deaf 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.