PCI/PM: Add ABI document for sysfs file d3cold_allowed

[linux.git] / Documentation / ABI / testing / sysfs-bus-pci

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index 34f51100f0299cb5a96a77984def99dbfdd9367d..dff1f48d252d8f0d36aa31cccf6514cb02b3d333 100644 (file)
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -210,3 +210,15 @@ Users:
                firmware assigned instance number of the PCI
                device that can help in understanding the firmware
                intended order of the PCI device.
+
+What:          /sys/bus/pci/devices/.../d3cold_allowed
+Date:          July 2012
+Contact:       Huang Ying <ying.huang@intel.com>
+Description:
+               d3cold_allowed is bit to control whether the corresponding PCI
+               device can be put into D3Cold state.  If it is cleared, the
+               device will never be put into D3Cold state.  If it is set, the
+               device may be put into D3Cold state if other requirements are
+               satisfied too.  Reading this attribute will show the current
+               value of d3cold_allowed bit.  Writing this attribute will set
+               the value of d3cold_allowed bit.