Red Hat Bugzilla – Bug 156705
Serial console corrupt on boot
Last modified: 2013-03-06 00:58:31 EST
When booting with serial console on a machine with a National Semiconductor
SuperIO chip where the BIOS enables its high speed mode, the initialisation of
the serial driver switches it into high-speed mode without fixing up the baud rate.
The result is that the port suddenly ends up running four times faster than it
should, and the last non-garbage thing we see on the serial console is the
serial driver's initialisation message.
The fix is to adjust the baud rate divisor at the same time as we adjust the
Created attachment 113967 [details]
patch to recalculate divisor as appropriate.
Created attachment 114075 [details]
This is the form in which the patch was sent upstream. With the original
problem fixed, the 'ifndef ppc' hack isn't required either.
*** Bug 158107 has been marked as a duplicate of this bug. ***
we added this to /etc/rc.sysinit as a workaround:
/bin/setserial /dev/ttyS0 spd_normal
/bin/stty 9600 < /dev/ttyS0
quite early, just after ". /etc/init.d/functions" worked for us. we don't get
all the boot messages, but it's workable.
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.
*** Bug 167117 has been marked as a duplicate of this bug. ***