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I am using Ubuntu Oneiric and have kept fully up-to-date with updates. My GPU is a Radeon HD6970, for which I am using the open-source Radeon drivers. The only change I have made to the 'default environment' is forcing the GPU to use a low power profile, by adding 'echo "low" > /sys/class/drm/card0/device/power_profile' to /etc/rc.local .

Whenever I suspend the machine through Ubuntu's power/settings menu, it sleeps just fine. After waking up however, obvious graphical glitches are present. Windows move remarkably less smooth and content in the browser is unreadable, for example. Hitting Alt+F2 and entering 'unity --replace', although moving all windows to the upper-left corner, fixes this.

Now I am looking for a more elegant, or at least a more automatic way of getting the job done. On IRC I was told to either fix the driver problems or add the aforementioned command in a pm-utils script. I am not sure how to do the latter, let alone the former.

Any ideas?

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Hello, welcome to AskUbuntu.com It is important to know what kind of changes you did, can you please specify how and where did your change the configuration and add that information to the question? –  Bruno Pereira Jan 3 '12 at 12:32
    
Thank you for your kind reception. I have added more specific information regarding the power setting. –  psalden Jan 3 '12 at 12:36

1 Answer 1

With pm-utils, you can use a simple scritp to change the power profile like this :

Just use this commands :

sudo gedit /usr/lib/pm-utils/power.d/ati

Copy this text in the ati file :

#!/bin/sh

case $1 in
    true) echo low > /sys/class/drm/card0/device/power_profile ;;
    false) echo high > /sys/class/drm/card0/device/power_profile ;;
    *) exit $NA ;;
esac

exit 0

And use this command to make it executable :

sudo chmod +x /usr/lib/pm-utils/power.d/ati

It works for me. On battery, I use the low profile and, on AC, I use the high profile.

You can use this profiles (https://wiki.archlinux.org/index.php/ATI) :

  • "default" uses the default clocks and does not change the power state. This is the default behavior.
  • "auto" selects between "mid" and "high" power states based on the whether the system is on battery power or not. The "low" power state are selected when the monitors are in the dpms off state.
  • "low" forces the gpu to be in the low power state all the time. Note that "low" can cause display problems on some laptops; this is why auto only uses "low" when displays are off.
  • "mid" forces the gpu to be in the "mid" power state all the time. The "low" power state is selected when the monitors are in the dpms off state.
  • "high" forces the gpu to be in the "high" power state all the time. The "low" power state is selected when the monitors are in the dpms off state.
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