[ltp] T430 video-related freeze in Discrete Graphics mode

[Kevin Locke]

Hey All,

I just thought I'd mention that I've been experiencing hard lockups
when loading the ACPI video module on a T430 when configured for
"Discrete Graphics" mode in the BIOS (also when using vga_switcheroo
to switch to discrete graphics, which may or may not be related).  I'm
not sure if others have been experiencing this issue, but it's
something to be aware of.

I've had success working around it by either passing "nox2apic" on the
kernel command line or by using the nvidia binary module and
blacklisting the video module (with the caveat that closing the lid
can hang the computer).

Aaron Lu has been exceedingly helpful in isolating the issue and I am
very grateful for all of his efforts.  If any of you are interested in
the gory details, take a look at
<https://bugzilla.kernel.org/show_bug.cgi?id=56051>.

Cheers,
Kevin