Linux – How to debug a Suspend-to-RAM issue on Linux

debugginglinuxsuspend

I'm hoping to get experience-based suggestions on how to go about debugging suspend-to-RAM issue. Advice specific to my situation(detailed below) would be great, but I am also interested in general advice about how to debug such issues.

The problem:

Often, when I attempt to suspend my machine, it gets stuck in a "not suspended but not awake" state. Often the screen will be completely black but sometimes it will have the following error message on it:

GLib-WARNING **: getpwuid_r(): failed due to unknown user id (0)

Also, this state will also be accompanied by the fans kicking into high gear. The only way to get it out of this state is to manually power off the laptop.

Some Information

$ uname -a
Linux baltar 2.6.35-22-generic #34-Ubuntu SMP Sun Oct 10 09:26:05 UTC 2010 x86_64 GNU/Linux

$ lsb_release -a
Distributor ID:    Ubuntu
Description:    Ubuntu 10.10
Release:    10.10
Codename:    maverick

I've taken a look at /var/log/dmesg and /var/log/pm-suspend.log, but I don't know what I'm looking for and nothing stands out. I'm unsure if it is related, but I did find a lot of the following in /var/log/kern.log:

EXT4-fs (dm-0): re-mounted. Opts: errors=remount-ro,commit=600

Best Answer

Do you have an Intel graphics chipset? I was getting what sounds like the same problem on my ThinkPad X200s running Ubuntu 10.10, and this workaround (from 2008!) fixed it for me: http://ubuntuforums.org/showpost.php?p=6105510&postcount=12

Related Solutions

Linux – Determine time of last suspend(-to-ram)

Your distribution has a power management framework (this is clear because it is already suspending itself) that runs some scripts when it is about to suspend/hibernate/shutdown as well as when it resumes/turns on. If you do a search for " power management", you should be able to find good documentation about it.

The task probably involves simply placing a script in an appropriate directory. That script can be as simple as date +%s > /var/last-wake-time. Then your existing script would simply look at that file.

In general, not every distribution comes with power management utilities, and there are several tools tools to look at. You can check out acpid, uPower, pm-utils, and laptop-mode tools.

Debugging Suspend Problems – How to Debug a Suspend Problem?

There are many ways to handle suspend and hibernate capabilities, many of the old methods are deprecated. This has made searching for solutions difficult, as it seems every solution is completely unrelated to the next. With that said...

The method currently recommended, advocated from http://pm-utils.freedesktop.org/wiki/, should be available for most recent distributions. I would first check if you have pm-utils installed, and if the included commands are operating as expected.

View if the package is installed, enter this command in terminal

rpm -qa | grep pm-utils

This should output the version you have installed. If you don't get the expected output, you need to install the package.

sudo yum install pm-utils

Once you get that verified, test out your ability to suspend.

sudo pm-suspend

If You don't suspend, and get no output why, check the your recent dmesg output

dmesg | tail -50

This should help get you started, once you get some clues its much easier to go further down the trail. Post back with comments regarding your results, I can get you through the rest.

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