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After a very long time that I suffer from this problem, I have decided to "ask ubuntu". I know there is quite a bit of information about this problem, but none had worked for me so far.

  • The symptoms:

    When pressing suspend in ubuntu, (every once in a while) the screen turns black and after a few seconds the fans start to work rapidly (apparently due to cpu usage). I had this problem both in ubuntu 12.04 and in 12.10 (after I upgraded).

    Many solutions have been suggested for this issue, but none seems to work for me. For example, there's this post:

    Entire system freezing after pressing “Suspend” [closed]

  • Clues for the cause of this problem, and what I have found out:

    First of all I should mention that I have an AMD Radeon HD 6470M GPU and have the AMD drivers installed (I do not use the proprietary drivers, because they don't handle the GPU as well as the AMD drivers). It is probable that this is the key for this issue.

    I have found a suggestion somewhere (but I can't find the link to the forum now), that Ubuntu should be sent to sleep using the shell commands: dbus-send --system --print-reply --dest="org.freedesktop.UPower" /org/freedesktop/UPower org.freedesktop.UPower.Suspend

    I can't remember if this requires for an installation of some package or not. Anyway, this seemed to work for me at the beginning, but shortly after I started using this command the problem returned.

  • Then I had an idea:

    It seemed to me that the problem appears because of the use of the AMD drivers and that when going to suspend the CPU is stuck in some infinite loop, so I have decided to monitor my processes and send the computer to sleep (using the script) only after the "compiz" process is not using the cpu (monitoring with "system monitor"). This may seem to be an odd idea, but it seems to work almost completely.

    Nowadays, I send Ubuntu to suspend using the above script when I see that all processes are idle (there's no CPU usage), and it works without any problem almost every time. Unfortunately, every other time Ubuntu freezes as before. But these occurrences are more rare then they used to be.

Update (as of Oct. 26th, 2013) - A (flimsy) solution:

After some more tests, it seems that the following method works:

  1. Open the "System monitor" and choose the "processes" tab. Make sure to choose the option View->All Processes.
  2. Before dispatching a suspend request, wait for the processes "compiz" and "Xorg" to reach idle use of the cpu.
  3. Request a suspend using the commands (in the terminal):

    dbus-send --system --print-reply     --dest="org.freedesktop.UPower"     /org/freedesktop/UPower     org.freedesktop.UPower.Suspend
    

(using the Ubuntu "suspend" shortcut may work as well. I havent tested it yet).

Obviously, this isn't an ideal solution, but it gets the job done. This is the most I can do with my knowledge of linux.

So, the call for help is still on. If anybody have any idea how to finally solve this problem, or further debugging it, any help will be appreciated.

share|improve this question

closed as off-topic by Jorge Castro, Braiam, chaskes, Lucio, guntbert Nov 2 '13 at 20:28

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Bug reports and problems with the development version of Ubuntu should be reported on Launchpad so that developers can see, track and fix these issues." – Jorge Castro, Braiam, chaskes, Lucio, guntbert
If this question can be reworded to fit the rules in the help center, please edit the question.

    
Mm... those issues normally has to do with the kernel. I recommend you reporting a bug. –  Braiam Nov 2 '13 at 1:14
    
This is just the kind of info you need to share with the devs in your bug report. –  chaskes Nov 2 '13 at 1:34

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