USB: add remove_id sysfs attr for usb drivers

Accroding commit 0994375e, which is adding remove_id sysfs attr
for pci drivers, for management tools dynamically bind/unbind
a pci/usb devices to a specified drivers; with this patch,
the management tools can be simplied.

And the original code didn't handle the failure of
usb_create_newid_file, fixed in this patch.

Signed-off-by: CHENG Renquan <rqcheng@smu.edu.sg>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 13 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb
index 7772928ee48f..deb6b489e4e5 100644
--- a/Documentation/ABI/testing/sysfs-bus-usb
+++ b/Documentation/ABI/testing/sysfs-bus-usb
@@ -144,3 +144,16 @@ Description:
 
                 Write a 1 to force the device to disconnect
                 (equivalent to unplugging a wired USB device).
+
+What:           /sys/bus/usb/drivers/.../remove_id
+Date:           November 2009
+Contact:        CHENG Renquan <rqcheng@smu.edu.sg>
+Description:
+                Writing a device ID to this file will remove an ID
+                that was dynamically added via the new_id sysfs entry.
+                The format for the device ID is:
+                idVendor idProduct.     After successfully
+                removing an ID, the driver will no longer support the
+                device.  This is useful to ensure auto probing won't
+                match the driver to the device.  For example:
+                # echo "046d c315" > /sys/bus/usb/drivers/foo/remove_id