console issue since 3.6, console=ttyS1 hangs

[Nathan Zimmer]

A cluster client recently tried to update from Sles11 to Sles12 and found in
some cases the boxes would hang in early boot.  It came down to console=ttyS1
on the command line.  After a bisection I found it happended in here:

commit 835d844d1a28efba81d5aca7385e24c29d3a6db2
Author: Sean Young <sean@xxxxxxxx>
Date:   Fri Sep 7 19:06:23 2012 +0100

    8250_pnp: do pnp probe before legacy probe


I found I can revert the part of the patch in 8250.c (now 8250_core.c) and
the hangs do not happen.

Bios of the offending box ( I don't know if there a bios update )
Version 2.15.1234. Copyright (C) 2012 American Megatrends, Inc.
BIOS Date: 02/05/2014 13:45:09
Ver: ma2e2054.16I

I don't have much more info but will collect anything that is asked.
Any help would be appeciated.

Nate