--- /dev/null
+From 0a3c8549ea7e94d74a41096d42bc6cdf43d183bf Mon Sep 17 00:00:00 2001
+From: Alan Stern <stern@rowland.harvard.edu>
+Date: Wed, 27 May 2009 11:25:52 -0400
+Subject: usb-serial: fix crash when sub-driver updates firmware
+
+From: Alan Stern <stern@rowland.harvard.edu>
+
+commit 0a3c8549ea7e94d74a41096d42bc6cdf43d183bf upstream.
+
+This patch (as1244) fixes a crash in usb-serial that occurs when a
+sub-driver returns a positive value from its attach method, indicating
+that new firmware was loaded and the device will disconnect and
+reconnect. The usb-serial core then skips the step of registering the
+port devices; when the disconnect occurs, the attempt to unregister
+the ports fails dramatically.
+
+This problem shows up with Keyspan devices and it might affect others
+as well.
+
+When the attach method returns a positive value, the patch sets
+num_ports to 0. This tells usb_serial_disconnect() not to try
+unregistering any of the ports; instead they are cleaned up by
+destroy_serial().
+
+Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
+Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
+
+---
+ drivers/usb/serial/usb-serial.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+--- a/drivers/usb/serial/usb-serial.c
++++ b/drivers/usb/serial/usb-serial.c
+@@ -973,6 +973,7 @@ int usb_serial_probe(struct usb_interfac
+ if (retval > 0) {
+ /* quietly accept this device, but don't bind to a
+ serial port as it's about to disappear */
++ serial->num_ports = 0;
+ goto exit;
+ }
+ }