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samwise

Member

From: Sydney, Australia

Registered: 2008-07-26

Posts: 53

Website

[SOLVED] Completely disabling the lid switch on a laptop

I have a Dell Inspiron 6400 that has been heavily used for a few years now. When I first set up automatic pm-suspend on lid closing, I found that I didn't have to do anything to get it to turn back on when the lid was re-opened, and I thought this was a win.

However now the lid switch is screwing up, so what happens is, I suspend it, shut the lid, put it in my bag, and then the lid switch will trip accidently and turn the laptop back on; so that when I take it out of my bag I find it's been switched on for half an hour and really really hot.

So what I want to do is completely disable the laptop lid switch, so that suspend is only entered and exited manually with Fn-Suspend and the power button (btw, I've already set that up).

I've disabled every software auto-suspend option I can find, removed my original ACPI lid switch handler scripts, but it still happens. I looked for a BIOS option to turn off the ACPI lid switch, but there doesn't seem to be one. Is it possible I need to change a HAL policy somewhere? I'm even willing to try a hard-hack solution if someone knows how to take apart dells.

Last edited by samwise (2009-05-25 10:29:22)

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"He was perfect except for the fact that he was an engineer"

ngoonee

Forum Fellow

From: Between Thailand and Singapore

Registered: 2009-03-17

Posts: 7,358

Re: [SOLVED] Completely disabling the lid switch on a laptop

I don't have access to any dells at the moment, but if I remember rightly, couldn't you sort of tape down the jutting-out switch?

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samwise

Member

From: Sydney, Australia

Registered: 2008-07-26

Posts: 53

Website

Re: [SOLVED] Completely disabling the lid switch on a laptop

I've done a bit more googling and research, and seem to have found a possible solution.

References:
Thinkwiki 'Talk: How to make ACPI work'
Ubuntu forums: 'How do I prevent resume on lid open?'

This appears to be controlled by the '/proc/acpi/wakeup' procfile. If you cat it, it shows all the possible wakeup sources and if they are disabled or enabled.

 LID       S3            *enabled
PBTN       S4            *enabled
MBTN       S4             disabled
USB0       33             disabled
...

I then did:

echo " LID" > /proc/acpi/wakeup

as root. (The space is important, all entries must be 4 characters apparently)

Unfortunately, this also disables the PBTN entry. Dmesg says:

ACPI: 'PBTN' and 'LID' have the same GPE, can't disable/enable one seperately

However, the power button still seems to trigger a wakeup, while the lid switch does not!

edit:The fix doesn't persist between reboots, so I added the above echo command to '/etc/rc.local'

Last edited by samwise (2009-05-25 10:29:04)

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"He was perfect except for the fact that he was an engineer"

samwise

Member

From: Sydney, Australia

Registered: 2008-07-26

Posts: 53

Website

Re: [SOLVED] Completely disabling the lid switch on a laptop

I don't have access to any dells at the moment, but if I remember rightly, couldn't you sort of tape down the jutting-out switch?

This one doesn't have a jutting-out switch, unfortunately

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"He was perfect except for the fact that he was an engineer"