Arch Linux

davvil

Member

Registered: 2008-05-06

Posts: 165

Deactivating devices?

Is there any way to make sure a built-in device is deactivated? Let me explain: in my netbook (Samsung NC10) if I run powertop one of the causes of wakeups is the builtin webcam, which 99% of the time I'm not using (and the module is not loaded). In another laptop (Lenovo T500) I have two built-in graphic cards, one intel on-board which is the one I use in linux and one discrete ATI which I use for the occasional gaming in windows. If I activate both graphic cards in the bios the battery life of the laptop is reduced roughly to one half, although I am only using the on-board card. Is there any way to deactivate these devices so that they do not consume any power?

I also have a suspicion that this may also provide some hint for my other issue here http://bbs.archlinux.org/viewtopic.php?id=80978

takedown

Member

From: Argentina

Registered: 2008-08-31

Posts: 219

Re: Deactivating devices?

I have too a thinkpad T500 and for the graphic card I disable it in the BIOS.

In many places (forums and wiki) I read that to disable a hardware, the choice was not loading the driver. I think that figure is wrong (would be good to correct this concept in the corresponding articles in the wiki).

In the gentoo wiki say: more info
"When the BIOS is set to switchable, both graphics cards are powered; not only that, the ATI card clock will be at its highest speed unless the X graphics driver has stepped it down. For this reason, your laptop will get very, very hot. You might want to remove your laptop's battery until you managed to get a configuration which keeps your laptop cool."

   
I think the best way to solve this is by telling the driver to activate the energy saving. Or turn off the hardware in the BIOS

Last edited by takedown (2009-11-04 15:08:35)

davvil

Member

Registered: 2008-05-06

Posts: 165

Re: Deactivating devices?

Yes for the T500 the option of disabling one of the graphic cards in the BIOS is there. It is a bit of an inconvenience, having to change the setting every time I switch OS, but I can live with that.

Why does the gentoo wiki points out to removing the battery because of the heat? Is it the most (the only?) sensitive part to heat? This could be a solution. Now that I have the netbook the T500 is mainly a desktop replacement and for the times I take it away I can put the battery back and activate the Intel card.

However the general question still remains. Isn't there a (general?) way to truly deactivate built-in devices like webcams, bluetooth and so on?