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Author Topic: vga_switcheroo with latest kernels  (Read 2634 times)

Offline delta9

  • User
  • Posts: 20
vga_switcheroo with latest kernels
« on: 2013/11/20, 14:58:33 »

i have a lenovo notebook that comes with two graphic cards, an ati and an intel one.

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00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 12)
01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Madison [Mobility Radeon HD 5730 / 6570M] (rev ff)

The ati is completely useless for me and also makes my noetebook very noisy, so i use vga_switcheroo to shut it down at every boot and use only the intel.

Well. with the lastest kernels, this will not work.

Ok, first we check if the kernel is compiled with the proper option

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# grep -i switcheroo /boot/config-*

It says here,
"The vga_switcheroo mechanism will only be active when the kernel is booted with either the "modeset=1" kernel option, and/or the "nomodeset" option being absent."

In order to be able to access vgaswitcheroo i add this line to fstab:
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none                                          /sys/kernel/debug    debugfs      defaults                                     0    0
Then to test if vga_switcheroo is enabled

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delta9# ls -l /sys/kernel/debug/vgaswitcheroo/switch
-rw-r--r-- 1 root root 0 Nov 20 14:39 /sys/kernel/debug/vgaswitcheroo/switch

And To shut down the ati card

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echo OFF > /sys/kernel/debug/vgaswitcheroo/switchFor the last one i mad e a simple script and placed it in init.d to run at ever boot.

It also says here https://wiki.archlinux.org/index.php/hybrid_graphics that KMS must be activated for both cards, otherwise there will be no vgaswitcheroo in /sys/kernel/debug/

Problem is that with kernel 3.9-3.towo-siduction-amd64 to 3.12-0.towo-siduction-amd64 this will not work and i get this error message
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# ls -l /sys/kernel/debug/vgaswitcheroo/switch
ls: cannot access /sys/kernel/debug/vgaswitcheroo/switch: No such file or directory

The last working kernel is kernel 3.9-2.towo-siduction-amd64 wich gives

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# ls -l /sys/kernel/debug/vgaswitcheroo/switch
-rw-r--r-- 1 root root 0 Nov 20 14:39 /sys/kernel/debug/vgaswitcheroo/switch

I should also mention that last working kernel from 3.8- is kernel 3.8-3.towo-siduction-amd64
and from 3.7- is kernel 3.7-10.towo-siduction-amd64

Any help would be apreciated,

Thnanks a lot in advance