PCI/PM: Add ABI document for sysfs file d3cold_allowed

This patch adds ABI document for the following sysfs file:

/sys/bus/pci/devices/.../d3cold_allowed

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>

1 files changed, 12 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index 34f51100f029..dff1f48d252d 100644
--- 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.