dynamic_debug: update Documentation/*, Kconfig.debug

In dynamic-debug-howto.txt:

- add section: Debug Messages at Module Initialization Time
- update flags indicators in example outputs to include '='
- make flags descriptions tabular
- add item on '_' flag-char
- add dyndbg, boot-args examples
- rewrap some paragraphs with long lines

In Kconfig.debug, note that compiling with -DDEBUG enables all
pr_debug()s in that code.

In kernel-parameters.txt, add dyndbg and module.dyndbg items,
and deprecate ddebug_query.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/kernel-parameters.txt

@@ -610,7 +610,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 
 	ddebug_query=   [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot
 			time. See Documentation/dynamic-debug-howto.txt for
-			details.
+			details.  Deprecated, see dyndbg.
 
 	debug		[KNL] Enable kernel debugging (events log level).
 
@@ -730,6 +730,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 
 	dscc4.setup=	[NET]
 
+	dyndbg[="val"]		[KNL,DYNAMIC_DEBUG]
+	module.dyndbg[="val"]
+			Enable debug messages at boot time.  See
+			Documentation/dynamic-debug-howto.txt for details.
+
 	earlycon=	[KNL] Output early console device and options.
 		uart[8250],io,<addr>[,options]
 		uart[8250],mmio,<addr>[,options]

lib/Kconfig.debug

@@ -1205,8 +1205,13 @@ config DYNAMIC_DEBUG
 	  otherwise be available at runtime. These messages can then be
 	  enabled/disabled based on various levels of scope - per source file,
 	  function, module, format string, and line number. This mechanism
-	  implicitly enables all pr_debug() and dev_dbg() calls. The impact of
-	  this compile option is a larger kernel text size of about 2%.
+	  implicitly compiles in all pr_debug() and dev_dbg() calls, which
+	  enlarges the kernel text size by about 2%.
+
+	  If a source file is compiled with DEBUG flag set, any
+	  pr_debug() calls in it are enabled by default, but can be
+	  disabled at runtime as below.  Note that DEBUG flag is
+	  turned on by many CONFIG_*DEBUG* options.
 
 	  Usage:
 
@@ -1223,16 +1228,16 @@ config DYNAMIC_DEBUG
 	  lineno : line number of the debug statement
 	  module : module that contains the debug statement
 	  function : function that contains the debug statement
-          flags : 'p' means the line is turned 'on' for printing
+          flags : '=p' means the line is turned 'on' for printing
           format : the format used for the debug statement
 
 	  From a live system:
 
 		nullarbor:~ # cat <debugfs>/dynamic_debug/control
 		# filename:lineno [module]function flags format
-		fs/aio.c:222 [aio]__put_ioctx - "__put_ioctx:\040freeing\040%p\012"
-		fs/aio.c:248 [aio]ioctx_alloc - "ENOMEM:\040nr_events\040too\040high\012"
-		fs/aio.c:1770 [aio]sys_io_cancel - "calling\040cancel\012"
+		fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
+		fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
+		fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
 
 	  Example usage: