Re: Fatal trap 12 during bootup on Dell Cpt with acpi enabled

[YONETANI Tomokazu <qhwt+dfly@xxxxxxxxxx>]

On Tue, Mar 09, 2010 at 03:50:34PM -0800, LordYoukai wrote:
> current process = Idle
> current thread = pri 12
> kernel: type 12 trap, code = 2
> Stopped at AcpiReadBitRegister+0x46:   movl %eax,0(%edx)

Since the current process is Idle and it's crashing somewhere in
AcpiReadBitRegister(), I guess that the caller is probably acpi_cpu_idle().
You can turn off part of ACPI subdrivers by setting boot loader variable
(you can find the names of other subdrivers in acpi(4)):
  set debug.acpi.disabled="cpu_cst"

and see if it still panics.

Alternatively, if you can modify the acpi code and reinstall the driver,
the following procedure may or may not fix the issue.

$ cd /sys/dev/acpica5
(if you don't have write access on /usr/obj, you need to set
 an environment variable MAKEOBJDIRPREFIX to somewhere else
 where you do)
$ make obj && make depend
$ sed -i.bak 's/cpu_quirks;/cpu_quirks = CPU_QUIRK_NO_BM_CTRL;/' acpi_cpu_cstate.c && make
(see if there's no compilation errors, and ...)
$ su root -c 'make install'

Cheers.