Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (46 commits)
  UIO: Fix mapping of logical and virtual memory
  UIO: add automata sercos3 pci card support
  UIO: Change driver name of uio_pdrv
  UIO: Add alignment warnings for uio-mem
  Driver core: add bus_sort_breadthfirst() function
  NET: convert the phy_device file to use bus_find_device_by_name
  kobject: Cleanup kobject_rename and !CONFIG_SYSFS
  kobject: Fix kobject_rename and !CONFIG_SYSFS
  sysfs: Make dir and name args to sysfs_notify() const
  platform: add new device registration helper
  sysfs: use ilookup5() instead of ilookup5_nowait()
  PNP: create device attributes via default device attributes
  Driver core: make bus_find_device_by_name() more robust
  usb: turn dev_warn+WARN_ON combos into dev_WARN
  debug: use dev_WARN() rather than WARN_ON() in device_pm_add()
  debug: Introduce a dev_WARN() function
  sysfs: fix deadlock
  device model: Do a quickcheck for driver binding before doing an expensive check
  Driver core: Fix cleanup in device_create_vargs().
  Driver core: Clarify device cleanup.
  ...

1 files changed, 55 insertions, 0 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index aa81d284844..31d784dd80d 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -807,6 +807,61 @@ menuconfig BUILD_DOCSRC
 
           Say N if you are unsure.
 
+config DYNAMIC_PRINTK_DEBUG
+        bool "Enable dynamic printk() call support"
+        default n
+        depends on PRINTK
+        select PRINTK_DEBUG
+        help
+
+          Compiles debug level messages into the kernel, which would not
+          otherwise be available at runtime. These messages can then be
+          enabled/disabled on a per module basis. 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%.
+
+          Usage:
+
+          Dynamic debugging is controlled by the debugfs file,
+          dynamic_printk/modules. This file contains a list of the modules that
+          can be enabled. The format of the file is the module name, followed
+          by a set of flags that can be enabled. The first flag is always the
+          'enabled' flag. For example:
+
+                <module_name> <enabled=0/1>
+                                .
+                                .
+                                .
+
+          <module_name> : Name of the module in which the debug call resides
+          <enabled=0/1> : whether the messages are enabled or not
+
+          From a live system:
+
+                snd_hda_intel enabled=0
+                fixup enabled=0
+                driver enabled=0
+
+          Enable a module:
+
+                $echo "set enabled=1 <module_name>" > dynamic_printk/modules
+
+          Disable a module:
+
+                $echo "set enabled=0 <module_name>" > dynamic_printk/modules
+
+          Enable all modules:
+
+                $echo "set enabled=1 all" > dynamic_printk/modules
+
+          Disable all modules:
+
+                $echo "set enabled=0 all" > dynamic_printk/modules
+
+          Finally, passing "dynamic_printk" at the command line enables
+          debugging for all modules. This mode can be turned off via the above
+          disable command.
+
 source "samples/Kconfig"
 
 source "lib/Kconfig.kgdb"