USB: fix interface sysfs file-creation bug

This patch (as1005) fixes a rather subtle problem.  When
usb_set_configuration() registers the interfaces and their files in
sysfs, it doesn't expect those files to exist already.  But when an
interface is registered, its driver may call usb_set_interface() and
thereby cause the sysfs files to be created.  The result is an error
when usb_set_configuration() goes on to create those same files again.

The (not-so-great) solution is to have usb_set_configuration() remove
any existing files before creating them.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 7 insertions, 1 deletions

diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 8bdaa157ffe7..eb4ac47612a5 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1641,7 +1641,13 @@ free_interfaces:
                                 intf->dev.bus_id, ret);
                         continue;
                 }
-                usb_create_sysfs_intf_files (intf);
+
+                /* The driver's probe method can call usb_set_interface(),
+                 * which would mean the interface's sysfs files are already
+                 * created.  Just in case, we'll remove them first.
+                 */
+                usb_remove_sysfs_intf_files(intf);
+                usb_create_sysfs_intf_files(intf);
         }
 
         usb_autosuspend_device(dev);