1 files changed, 26 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-firmware-acpi b/Documentation/ABI/testing/sysfs-firmware-acpi
index dd930c8db41f..ce9bee98b43b 100644
--- a/Documentation/ABI/testing/sysfs-firmware-acpi
+++ b/Documentation/ABI/testing/sysfs-firmware-acpi
@@ -18,6 +18,32 @@ Description:
                 yoffset: The number of pixels between the top of the screen
                          and the top edge of the image.
 
+What:           /sys/firmware/acpi/hotplug/
+Date:           February 2013
+Contact:        Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+Description:
+                There are separate hotplug profiles for different classes of
+                devices supported by ACPI, such as containers, memory modules,
+                processors, PCI root bridges etc.  A hotplug profile for a given
+                class of devices is a collection of settings defining the way
+                that class of devices will be handled by the ACPI core hotplug
+                code.  Those profiles are represented in sysfs as subdirectories
+                of /sys/firmware/acpi/hotplug/.
+
+                The following setting is available to user space for each
+                hotplug profile:
+
+                enabled: If set, the ACPI core will handle notifications of
+                        hotplug events associated with the given class of
+                        devices and will allow those devices to be ejected with
+                        the help of the _EJ0 control method.  Unsetting it
+                        effectively disables hotplug for the correspoinding
+                        class of devices.
+
+                The value of the above attribute is an integer number: 1 (set)
+                or 0 (unset).  Attempts to write any other values to it will
+                cause -EINVAL to be returned.
+
 What:           /sys/firmware/acpi/interrupts/
 Date:           February 2008
 Contact:        Len Brown <lenb@kernel.org>