[ltp] ACPI Lid switch control

Dmitry E. Mikhailov linux-thinkpad@linux-thinkpad.org
Mon, 2 Jun 2008 00:09:14 +0600

> > I have a T61 with Hardy. Everything works like charm. (very occasional
> > kernel panics)
> "very occasional kernel panics" does not mean "works like a charm" you
> should really investigate into these panics, maybe its even a hardware
> problem ...
Hey, I got not a single kernel panic 'till the Migration (from 'other OS', you 
know ;-)) on my X41. That was 2.6.18 kernel. Now it's 2.6.25 and still it's 
as stable as a rock. So as Flyser suggested, you should investigate your 
oopses. Until you use a bleeding edge kernel, oopses usually indicate dying 
hardware. Start with the RAM check. And I hope you don't practice 
undervolting your CPU 'cos hardware working out of spec generates random-bit 

> > So I suppose I need to disable the ACPI lid switch off at a lower level.
> > I'm I right?
> > How do I do that?
> I would suggest to file a bug on launchpad, the ubuntu bugtracker, this
> should not require low-level modifications in ubuntu.
Wait a little bit with filling a bug. If you don't use acpid then try this:

Disable ACPI lid support

You can also disable ACPI LID support completely. The following advice has 
been copied straight from widan's post on the Gentoo forums (Acer Travelmate 
8100 continuous acpi events): 
Something you can try (but I don't know if it will work, and it's only a 
workaround): open the file /usr/src/linux/drivers/acpi/button.c, and look for 
that line (it's around line 80): 
Replace it by that one: 
.ids =      "ACPI_FPB,ACPI_FSB,PNP0C0C,PNP0C0E", 
Recompile the kernel, install it, and reboot. Now the lid switch handling 
should be disabled (you can check it by verifying that the "ACPI: Lid Switch 
[LID]" line disappeared in dmesg).

Tip taken from here: 

Best regards, Dmitry