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>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/usb.h b/include/linux/usb.h
index 8fa973bede5e..f72aa51f7bcd 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -108,6 +108,7 @@ enum usb_interface_condition {
  *      (in probe()), bound to a driver, or unbinding (in disconnect())
  * @is_active: flag set when the interface is bound and not suspended.
  * @sysfs_files_created: sysfs attributes exist
+ * @unregistering: flag set when the interface is being unregistered
  * @needs_remote_wakeup: flag set when the driver requires remote-wakeup
  *      capability during autosuspend.
  * @needs_altsetting0: flag set when a set-interface request for altsetting 0
@@ -163,6 +164,7 @@ struct usb_interface {
         enum usb_interface_condition condition;         /* state of binding */
         unsigned is_active:1;           /* the interface is not suspended */
         unsigned sysfs_files_created:1; /* the sysfs attributes exist */
+        unsigned unregistering:1;       /* unregistration is in progress */
         unsigned needs_remote_wakeup:1; /* driver requires remote wakeup */
         unsigned needs_altsetting0:1;   /* switch to altsetting 0 is pending */
         unsigned needs_binding:1;       /* needs delayed unbind/rebind */