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When IGD and DIS both exist in my pc,and I want to disable DIS,so I create a service to switch on and off the DIS.It works.Finally,I decide to add the service command into /etc/rc.local so that DIS will be powered off automatically.Unfortunately,it fails.There's only one command added by myself in the file /etc/rc.local,so I can affirm failure is caused by that added command.

Before,I directly added the command "echo OFF >/sys/kernel/debug..." into /etc/rc.local,and when I restarted,the system startup fails.So I thought maybe when the command is executed,the DIS hasn't been powered on or ready for work.So conflict occurs!It's just my prediction.Then I added one line command "sleep 1s" before the "echo OFF ...",it works nearly everytime when I start or restart pc,while fails sometimes.

The output result of "cat /sys/kernel/debug..." is as following: 0:IGD:+:Pwr:0000:00:02.0 1:DIS: :Pwr:0000:01:00.0

I want know 0000:00:02.0 means what?Time of first power on? If it was really time,I can set the command "sleep 2s" to wait for DIS powered on then "echo OFF > ..."

Thanks for your advice!

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It doesn't matter. For more info, see this page.

You can edit /etc/rc.local and add the next lines:

sleep 6
echo ON > /sys/kernel/debug/vgaswitcheroo/switch 
echo IGD > /sys/kernel/debug/vgaswitcheroo/switch
echo OFF > /sys/kernel/debug/vgaswitcheroo/switch

Then save the file and restart.

For me, this worked. The sleep 1 or 2 is too early and it makes the system frozen.

Try and tell me what are the results. (Use it at your own risk. I only tested in my system.)

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