[ltp] T61/intel: LCD brightness

[Theodore Tso]

On Mon, Oct 29, 2007 at 12:17:17PM -0200, Henrique de Moraes Holschuh wrote:
> > > Yes.  Since you are using Ubuntu, you must use thinkpad-acpi 0.18. 0.14
> > > cannot handle 16 levels, because Ubuntu insists on messing with the display
> > > brightness through thinkpad-acpi.
> > > 
> > > You need a very recent kernel (2.6.22 recommended as 2.6.23.1 is broken),
> > > and thinkpad-acpi 0.18.
> > 
> > Also make sure you either have disabled CONFIG_ACPI_VIDEO, or build
> > thinkpad-acpi as module and then make sure it is loaded with the
> > parameter brightness_enable=1.
> 
> That suggests that the 2.6.22 video module is broken?

No, only that Ubuntu insists to make adjustments via thinkpad-acpi,
and if the video module is loaded, the default is for
/proc/acpi/ibm/brightness to not be visible, unless you override this
with brightness_enable=1.  One could call this Ubuntu being broken, or
thinkpad_acpi not being sufficiently backwards compatible, but
whatever, this is easy enough to work around with an entry in
/etc/modutils/thinkpad-acpi.

							- Ted