Comment 17 for bug 1261853

Alex Barattini, thank you for advising on the potential fix commit. Regarding it http://www.spinics.net/lists/linux-acpi/msg47755.html , in order to test this patch, start by copying from the line where it notes:
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c

to the last code line before the double dash:
 static int register_count;

Your patch file should be exactly as shown, honoring all spaces, or lack thereof:
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 995e91b..b3032f8 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -85,7 +85,7 @@ module_param(allow_duplicates, bool, 0644);
  * For Windows 8 systems: if set ture and the GPU driver has
  * registered a backlight interface, skip registering ACPI video's.
  */
-static bool use_native_backlight = false;
+static bool use_native_backlight = true;
 module_param(use_native_backlight, bool, 0644);

 static int register_count;

save this file to your Desktop as testfix.patch. Then execute at a terminal:
git config --global user.email "<email address hidden>" && git config --global user.name "Your Name" && git clone git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git ~/Desktop/linux-stable && patch ~/Desktop/linux-stable/drivers/acpi/video.c ~/Desktop/testfix.patch && git add . && git commit

Now in the new window type:
example

press Ctrl+O -> Enter -> Ctrl+X. Then, type at a terminal:
git log -n 1 | grep commit

which should post the commit:
commit <COMMIT>

Use this commit in the below terminal command:
git checkout <COMMIT> && cp /boot/config-`uname -r` .config && yes '' | make oldconfig && make-kpkg clean && CONCURRENCY_LEVEL=`getconf _NPROCESSORS_ONLN` fakeroot make-kpkg --initrd --append-to-version=-custom2 kernel_image kernel_headers && cd .. && sudo dpkg -i *.deb

If for whatever reason the new kernel doesn't boot, it may not be you did something wrong, but just that it won't boot with this commit.