USB: don't register endpoints for interfaces that are going away

This patch (as1155) fixes a bug in usbcore.  When interfaces are
deleted, either because the device was disconnected or because of a
configuration change, the extra attribute files and child endpoint
devices may get left behind.  This is because the core removes them
before calling device_del().  But during device_del(), after the
driver is unbound the core will reinstall altsetting 0 and recreate
those extra attributes and children.

The patch prevents this by adding a flag to record when the interface
is in the midst of being unregistered.  When the flag is set, the
attribute files and child devices will not be created.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org> [2.6.27, 2.6.26, 2.6.25]
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 8877385..6d1048f 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1091,6 +1091,7 @@
 				continue;
 			dev_dbg(&dev->dev, "unregistering interface %s\n",
 				dev_name(&interface->dev));
+			interface->unregistering = 1;
 			usb_remove_sysfs_intf_files(interface);
 			device_del(&interface->dev);
 		}