Comment 14 for bug 1318299

Before performing the reverse bisect process I thought to ask directly in the linux-acpi mailing list which was the patch (or the set of patches) that have fixed the acpi/backlight issue .

This is the answer:
(original message http://marc.info/?l=linux-acpi&m=140429106012604&w=2)

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"I think you will need at least:

commit fbc9fe1b4f222a7c575e3bd8e9defe59c6190a04
Author: Aaron Lu <email address hidden>
Date: Fri Oct 11 21:27:45 2013 +0800

    ACPI / video: Do not register backlight if win8 and native interface exists

commit 0e9f81d3b7cd0649a3bc437391b6a0650f98f844
Author: Aaron Lu <email address hidden>
Date: Tue Feb 18 13:54:20 2014 +0800

    ACPI / video: Add systems that should favour native backlight interface

commit 751109aad5834375ca9ed0dcfcd85a00cbf872b5
Author: Rafael J. Wysocki <email address hidden>
Date: Thu Jun 5 22:47:35 2014 +0200

    ACPI / video: Change the default for video.use_native_backlight to 1

Maybe others, you will need to figure them out."
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I hope this will be helpful.
Also, the first good working kernel is v3.16rc1.

As long as I understand, instead of using a blacklist they have changed the default setup for the machines that are supporting Windows 8 with intel drivers. It seems that most of them don't use acpi. (More details starting from here http://lists.freedesktop.org/archives/intel-gfx/2013-October/034212.html)