hybrid graphics / vga_switcheroo

carick · 2010-07-31 14:18:35

My new laptop, HP dm4t comes with an integrated intel card and a discrete ATI card (5450). I am trying to figure out how to turn of the ATI card. I could not find how to determine the state of the card or how to turn it off. Any help would be appreciated.

Thanks

karol · 2010-07-31 14:25:28

Check in the BIOS, maybe simply not loading the modules would do the trick.

carick · 2010-07-31 14:33:20

No option in BIOS, and if i do not load the module, how will I be able to check if it is not running?

I tried following http://www.andreas-demmer.de/en/2010/07 … p-envy-14/ but I do not have the directory /sys/kernel/debug/vga_switcheroo/

cinan · 2010-07-31 14:45:05

Do `zcat /proc/config.gz| grep switch'. If you can see '# CONFIG_VGA_SWITCHEROO is not set' you have to recompile your kernel and enable this option. And you must have >=2.6.34 (according to the article)

karol · 2010-07-31 14:47:43

'zgrep switch /proc/config.gz' doesn't show anything here.
Running stock Arch kernel (I don't have two cards).

Edit: You have to use

zgrep -i switch /proc/config.gz

It shows 'CONFIG_VGA_SWITCHEROO=y' on a stock Arch kernel.

Last edited by karol (2010-07-31 17:23:03)

carick · 2010-07-31 15:36:38

yes, CONFIG_VGA_SWITCHEROO=y, as karol stated.

kgas · 2010-07-31 16:02:22

check this blog as a starting point.

carick · 2010-07-31 16:42:13

Is there not a way to determine devices have power? Besides the fact that the computer runs hotter than in windows, I have no idea if they are both on or what? That blog tells me do get a tool that doesn't compile:
<code>
make: *** /lib/modules/2.6.34-ARCH/build: no such file or directory. stop.
</code>

and doesnt tell me how? or why? I do not like to follow suggestions blindly.

toxygen · 2010-07-31 17:19:49

same problem here, on hp tm2, ati discrete card and intel built in card, no vgaswitcheroo listed in after mounting /sys/kernel/debug, no module listed, and switcheroo enabled in config. i have not played around with it long enough, nor have i tried rebuilding kernel, but methinks that vgaswitcheroo should be listed in debug if it was build with the kernel?

carick · 2010-07-31 18:34:39

The only thing that I can think of is that is has been moved from that location in the 2.6.34.1 release as it is no longer a "patch" but part of the official kernel.

Last edited by carick (2010-07-31 21:49:57)

toxygen · 2010-08-01 05:07:19

I did a search for switcheroo and only came up with

/usr/src/linux-2.6.34-ARCH/include/config/vga/switcheroo.h
/usr/src/linux-2.6.34-ARCH/include/linux/vga_switcheroo.h

so unless it's called something else it's not there.

Last edited by toxygen (2010-08-01 05:08:00)

takedown · 2010-08-01 18:31:11

try with this....http://asusm51ta-with-linux.blogspot.com/

carick · 2010-08-02 18:40:12

that tells you to do the same thing, although it goes through compiling the kernel with vga_switcheroo, which is already done with the "vanilla" arch kernel.

eldragon · 2010-08-02 18:52:58

the debug filesystem HAS to be mounted.

$  sudo mount -t debugfs debugfs /sys/kernel/debug

carick · 2010-08-02 21:48:28

mounting debugfs gives me some options in /sys/kernel/debug/ however, still none of them are vga_switcheroo.

toxygen · 2010-08-02 21:51:30

eldragon wrote:

the debug filesystem HAS to be mounted.
$  sudo mount -t debugfs debugfs /sys/kernel/debug

I [we] did mount it, as per instructions on those links above. but no vgaswitcheroo to be found anywhere!

koral · 2010-08-05 19:28:50

I do have this "vgaswitcheroo" folder in /sys/kernel/debug when I mount debugfs (using "mount -t debugfs none /sys/kernel/debug").
But I cannot modify /sys/kernel/debug/switch even as root. Anyone has an idea ?

grassmonk · 2010-08-05 20:56:18

At least for me, /sys/kernel/debug/vgaswitcheroo only appears if I have the radeon module loaded.

carick · 2010-08-05 22:48:34

I got it to work! I did 3 things, in this order.
- Syu (kernel 2.6.34.2)
- I added radeon to mkinitcpio.conf modules and make a new image
- Removed radeon.modeset=0 in grub

@koral, I was unable to echo OFF > /sys/kernel/debug/vgaswitcheroo/switch as a regular user or through sudo, but actually as root ( su -c '...' ) it worked fine.

Is there a way to mount debugfs and execute the echo at startup, as root? can I add debugfs to fstab? like none /sys/kernel/debug/ debugfs defaults 0 0 ?

toxygen · 2010-08-06 00:41:55

interesting, i'll have to try that later, i did not have radeon module loaded

jac · 2010-08-06 02:53:35

I've been messing around with this with an nvidia card, but most of the time it causes hard lockups and I can't switch cards, just turn off the discrete one.

@carick: What I've been doing is append it to rc.local, it's executed on startup as root right after everything else

carick · 2010-08-06 11:01:22

I assume you know you cannot switch cards while X is running.

jac · 2010-08-07 19:43:58

Yes, I know that. I think maybe I need to disable the frame buffer; I need to research more about it...

koral · 2010-08-19 13:47:59

When I switch (su -c "echo DIS > switch") in a console, without having started X server, everything freezes, and I have to reboot the computer. Any clue ?

koral · 2010-08-28 09:15:52

Up ?

Arch Linux

#1 2010-07-31 14:18:35

hybrid graphics / vga_switcheroo

#2 2010-07-31 14:25:28

Re: hybrid graphics / vga_switcheroo

#3 2010-07-31 14:33:20

Re: hybrid graphics / vga_switcheroo

#4 2010-07-31 14:45:05

Re: hybrid graphics / vga_switcheroo

#5 2010-07-31 14:47:43

Re: hybrid graphics / vga_switcheroo

#6 2010-07-31 15:36:38

Re: hybrid graphics / vga_switcheroo

#7 2010-07-31 16:02:22

Re: hybrid graphics / vga_switcheroo

#8 2010-07-31 16:42:13

Re: hybrid graphics / vga_switcheroo

#9 2010-07-31 17:19:49

Re: hybrid graphics / vga_switcheroo

#10 2010-07-31 18:34:39

Re: hybrid graphics / vga_switcheroo

#11 2010-08-01 05:07:19

Re: hybrid graphics / vga_switcheroo

#12 2010-08-01 18:31:11

Re: hybrid graphics / vga_switcheroo

#13 2010-08-02 18:40:12

Re: hybrid graphics / vga_switcheroo

#14 2010-08-02 18:52:58

Re: hybrid graphics / vga_switcheroo

#15 2010-08-02 21:48:28

Re: hybrid graphics / vga_switcheroo

#16 2010-08-02 21:51:30

Re: hybrid graphics / vga_switcheroo

#17 2010-08-05 19:28:50

Re: hybrid graphics / vga_switcheroo

#18 2010-08-05 20:56:18

Re: hybrid graphics / vga_switcheroo

#19 2010-08-05 22:48:34

Re: hybrid graphics / vga_switcheroo

#20 2010-08-06 00:41:55

Re: hybrid graphics / vga_switcheroo

#21 2010-08-06 02:53:35

Re: hybrid graphics / vga_switcheroo

#22 2010-08-06 11:01:22

Re: hybrid graphics / vga_switcheroo

#23 2010-08-07 19:43:58

Re: hybrid graphics / vga_switcheroo

#24 2010-08-19 13:47:59

Re: hybrid graphics / vga_switcheroo

#25 2010-08-28 09:15:52

Re: hybrid graphics / vga_switcheroo

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