On Mon, Oct 17, 2016 at 09:49:51AM -0500, Nathan Zimmer wrote:

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 [off-list ref]
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.

The console output would be helpful (both before 3.6 and with 3.6). It 
could be that what the bios provides in pnp does not match the actual
config.

The output of:

cat /sys/bus/pnp/drivers/serial/*/resources

Would be helpful, thanks.


Sean