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i wanted to install and use asus_switcheroo but unfortunately the vgaswitcheroo folder is missing. I already checked whether vgaswitcheroo is actually enabled and as i use the vanilla kernel it is (2.6.38-11-generic).

[EDIT] After looking a bit further into it it seems to help some people to enable kms on intel and radeon drivers to have the folder. Using this ubuntu forum post, add the following entries to the following file:

gksudo edit /etc/initramfs-tools/modules

Then add the following:

i915 modeset=1
nouveau modeset=1

close and run following command:

sudo update-initramfs -u

this lets the folder vgaswitcheroo appear again in debug (after reboot) however after installing asus-switcheroo and rebooting that folder will disappear again. with disabling:


which asus-switcheroo adds to /etc/initramfs-tools/modules

the directory reappears again, this solution however does not seem consistant and using this solution did not work either unfortunately however temporarely i could live with running:

instead i do this at the moment: at startup

cd /home/user/asus-switcheroo
make install-ubuntu

then doing whatever i want to and at shutdown

cd /home/user/asus-switcheroo
make uninstall-ubuntu

possible solution

played a little bit around and it seems that if I remove modeset=1 for nouveau and i915 and install asus-switcheroo it will work however when I echo OFF it does not bring the power saving I wanted but activating nvidia logging out -> in then activating intel logging out -> in saves more energy than using acpi_call.

and the problem with switcheroo disappearing is that it might reappear after a reebot seems rather buggy whether the folder will be available or not.

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there is a similar question here with lots of comments - please look through the comments and answer. Where there is a question, please add a response to an edit of your question. By doing this means we wont have to ask the same questions. Thanks.… – fossfreedom Aug 14 '11 at 15:26
@fossfreedom i already saw the link before thanks anyway but unfortunatly he solves the problem with enabling switching in the BIOS, this does not exist for the asus ul30vt bios version 211 anymore. I do feel like it could have something to do with [acpi_call] ( which i disabled for the time being however i will remove it and see whether the folder will appear – Kurosch Aug 14 '11 at 21:28
unfortunately removing acpi_call does not change anything if you want any files in the link from fossfreedom just tell me so i can add them to the question – Kurosch Aug 14 '11 at 21:59
excellent news - please add this as an answer (and you can accept your own answer) - otherwise the question will just keep going around this system. Many thanks. – fossfreedom Aug 15 '11 at 12:49
got a slight problem now after this it works as long as i do not install asus-switcheroo as soon this is installed vgaswitcheroo does disappear again. – Kurosch Aug 15 '11 at 21:44

I had the same problem: the folder vgaswitcheroo was missing. I found a solution: deactivate all proprietary drivers of your graphic card and then reboot. After that, the folder reappeared onto "/sys/kernel/debug". I hope it will help you !

share|improve this answer
Did not help me. – user24668 May 7 '12 at 19:21

I also had the same trouble. Adding the line below to /etc/fstab helped.

none            /sys/kernel/debug debugfs defaults 0 0

You might want to run the line below, to access there without rebooting.

mount /sys/kernel/debug

Note: There might be other reasons for vgaswitcheroo not showing up additional to this one. In my case other reasons were these;

  • I was powering down my discrete gpu on boot, so it wasn't even getting detected. (vga_switcheroo waits for a second gpu registration to enable itself)
  • For my card (radeon) I also needed to get vbios.bin in three places, /boot, /lib/firmware, and to initramfs
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