Fix Broken Standby


After setting my ThinkPad to standby mode it never woke up as I expected. In most cases I had to poweroff the whole machine, which is very ugly. I am using Ubuntu 8.04 and discovered the issue has not been fixed in the new 8.10 release.

In these days I read something interesting in the Ubuntu Forum

There was somebody who expected the problem arising from the multi core processor management. He suggested to disable one core before going to standby mode (suspend to ram). I tried it and it works perfectly!

So here’s the command to disable one core:

echo 0 > /sys/devices/system/cpu/cpu1/online

to enable it after wakeup, type

echo 1 > /sys/devices/system/cpu/cpu1/online

Of course, these actions have to be done as root