CCing debian-x@lists.debian.org and especially Maximillan Attems who prepared xserver-xorg-video-intel 2:2.99.911-git20140529-1~exp1 which added the backlight helper.
Summary of what happened so far: intel_backlight, which is default since Linux 3.16, does not work correctly on several laptops. They have been blacklisted in the kernel in order to use the working ACPI backlight again. #772440 is about just another laptop model to be added to this blacklist. Luca Boccassi found that the new backlight helper script in xserver-xorg-video-intel also fixes the issue. On 02/20/2015 12:29 AM, Luca Boccassi wrote: > Cross-post from freedesktop bug, just to make sure it doesn't go unnoticed: > > (In reply to Luca Boccassi from comment #13) >> Hello, >> >> I have a Dell Latitude E5540, running an Intel Haswell i7-4600U with GPU HD >> Graphics 4400, and I have the same problem. But I noticed that upgrading the >> Intel driver to a version that ships a new backlight helper binary fixes the >> problem. >> >> In my case, I am running Debian Jessie. The driver is part of the package >> xserver-xorg-video-intel and the version that ships the new backlight >> helper, according to the changelog, is: >> >> xserver-xorg-video-intel (2:2.99.911+git20140529-1~exp1) experimental; >> urgency=low >> >> * New upstream prerelease. (closes: #748753) >> * Install new backlight helper. Confirmed, in git://anonscm.debian.org/pkg-xorg/driver/xserver-xorg-video-intel I found the new backlight helper script to be the relevant commit. Also see the ongoing discussion in https://bugs.freedesktop.org/show_bug.cgi?id=87286. IMO the disable_native_backlight for some laptop models is (part of) the correct solution and it is not clear /why/ the new backlight helper script helps. Should we clone this bug as a more general one and then reassign to xserver-xorg-video-intel? We could then try to backport the changes to jessie to also help other affected laptops which are not yet blacklisted. That would be the following commits + probably some follow-up fixes. At least the 3rd commit requires manual merging: commit 631b4e4c78a807e61214026bf9a1461aadbd59b5 Author: maximilian attems <maks@***> Date: Thu May 29 17:07:16 2014 +0200 install add new helper commit b71f3d8bd4d6773899c1bdc903911cf240e68ead Author: Jan Alexander Steffens (heftig) <jan.steffens@***> Date: Sat Feb 15 17:53:16 2014 +0100 Backlight helper build fixes commit 3d629c91cfa98b75c6685c2a2003e64fd1b612c4 Author: Chris Wilson <chris@***> Date: Sat Feb 15 14:55:09 2014 +0000 intel: Add a helper for setting backlight without root rights I just fear it is too late for that in jessie. Greets jre -- To UNSUBSCRIBE, email to debian-x-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/54f0bb3c.9030...@gmail.com
