Comment 24 for bug 989674

For the record I have the same issue with 12.04 (64bit) on Lenovo L420 Thinkpad (Intel core-i5).

I had to get the latest BIOS (1.18) in order to get Ubuntu to install/boot without adding boot parameters.

I have tried multiple solutions, including the bind/unbind script that is posted here (I will try the chvt idea tonight, but
probably won't work because ^@F1 ^@F7 doesn't anyway).

"nolapic' in boot parameters fixes suspend but breaks hibernate, i.e.

With no extra boot parameters, hibernate/resume works, but suspend/resume hangs at black screen, unresponsive keyboard at resume
(after I hear the CD drive click).

When I put "nolapic" in the boot parameters, suspend/resume works, but hibernate/resume stops working.

When I say "hibernate" or "suspend" I am using "sudo pm-hibernate" and "sudo pm-suspend" to eliminate any other bugs (i.e. not
using the special keys to do it).

I have not got around to applying any fixes to the power settings menu, so that "hibernate" appears in it yet.

I have even tried the 'debugging resume problems' method (/sys.....pm_trace=1), but don't see anything in the logs that means
anything to me.

/var/log/pm-suspend.log shows failures on network manager, so I tried stopping it before suspend and also I tried modprobe'ing
out the two network drivers (wired and wireless), but that did not help either.

There is/are postings about doing something to the DSDT save/restore state that I have not got my head around yet, but probably
I will wait for the next proper update, so this is just a little posting to alert any other Thinkpad L420 / 64bit user that the
resume solution is an easy fix.