[Fujitsu Lifebook A512] Brightness hot keys Fn+F6/Fn+F7 don't work

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Jeremie Tamburini, thank you for reporting this and helping make Ubuntu better. Could you please test the latest upstream kernel available (3.15-rc7) following https://wiki.ubuntu.com/KernelMainlineBuilds ? It will allow additional upstream developers to examine the issue. Once you've tested the upstream kernel, please comment on which kernel version specifically you tested. If this bug is fixed in the mainline kernel, please add the following tags:
kernel-fixed-upstream
kernel-fixed-upstream-VERSION-NUMBER

where VERSION-NUMBER is the version number of the kernel you tested. For example:
kernel-fixed-upstream-3.15-rc6

This can be done by clicking on the yellow circle with a black pencil icon next to the word Tags located at the bottom of the bug description. As well, please remove the tag:
needs-upstream-testing

If the mainline kernel does not fix this bug, please add the following tags:
kernel-bug-exists-upstream
kernel-bug-exists-upstream-VERSION-NUMBER

As well, please remove the tag:
needs-upstream-testing

Once testing of the upstream kernel is complete, please mark this bug's Status as Confirmed. Please let us know your results. Thank you for your understanding.

Hi Christopher,

Tried the 3.15-rc7 kernel but the problem is still there. Pressing Fn+F6/Fn+F7 the brightness doesn't change.

Jeremie Tamburini, the issue you are reporting is an upstream one. Could you please report this problem through the appropriate channel by following the instructions _verbatim_ at https://wiki.ubuntu.com/Bugs/Upstream/kernel ?

Please provide a direct URL to your e-mail to the mailing list once you have made it so that it may be tracked.

Thank you for your understanding.

@Christopher
Here the bug report on the Linux mailing list: http://lkml.iu.edu//hypermail/linux/kernel/1406.0/00478.html
hope it's OK.

Jeremie Tamburini, the e-mail looks good, but you would want to redirect it to the linux-acpi mailing list, as this is where brightness issues tend to get addressed.

Right, this should be OK http://marc.info/?l=linux-acpi&m=140178030214298&w=2

Some good news.

I've tried the upstream kernel 3.16-rc2 and the brightness shortcut
"Fn+F6/Fn+F7" is now working out of the box without any workaround.

Jeremie Tamburini, the next step is to fully reverse commit bisect the kernel in order to identify the fix commit. Could you please do this following https://wiki.ubuntu.com/Kernel/KernelBisection#How_do_I_reverse_bisect_the_upstream_kernel.3F ?

Hi Christopher,
in the last couple of days I tried the kernels I didn't try before and now I can tell for sure that the fix arrived with the v3.16rc1 kernel. I also had a look at the bisect documentation and tried to move my first steps.

In the meantime Aaron Lu, the guy that was looking after the upstream bug-report, has answered my questions http://marc.info/?l=linux-acpi&m=140409199022683&w=2 about a possible bug-fix for the previous kernels (especially the 13.3). He replied:
"No chance for v3.13 as it lacks other supporting bits, sorry."

I've no skills to tell what it's better to do, but after Aaron's words I'm a bit afraid there will be a lot of work and still too many difficulties for the ubuntu-linux 3.13 bug-fix.

Jeremie Tamburini, Aaron Lu doesn't support the 3.13.x kernel series, the Ubuntu Kernel Team does. Despite this, the fix commit is still required as requested in https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1318299/comments/11 .

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)

--------------------------------
"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."
--------------------------------

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)