1 files changed, 8 insertions, 2 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb
index 1430f584b266..614d451cee41 100644
--- a/Documentation/ABI/testing/sysfs-bus-usb
+++ b/Documentation/ABI/testing/sysfs-bus-usb
@@ -50,13 +50,19 @@ Description:
                 This may allow the driver to support more hardware than
                 was included in the driver's static device ID support
                 table at compile time. The format for the device ID is:
-                idVendor idProduct bInterfaceClass.
+                idVendor idProduct bInterfaceClass RefIdVendor RefIdProduct
                 The vendor ID and device ID fields are required, the
-                interface class is optional.
+                rest is optional. The Ref* tuple can be used to tell the
+                driver to use the same driver_data for the new device as
+                it is used for the reference device.
                 Upon successfully adding an ID, the driver will probe
                 for the device and attempt to bind to it.  For example:
                 # echo "8086 10f5" > /sys/bus/usb/drivers/foo/new_id
 
+                Here add a new device (0458:7045) using driver_data from
+                an already supported device (0458:704c):
+                # echo "0458 7045 0 0458 704c" > /sys/bus/usb/drivers/foo/new_id
+
                 Reading from this file will list all dynamically added
                 device IDs in the same format, with one entry per
                 line. For example: