[MacBookAir6,2] LED-Panel Brightness not adjustable after suspend/resume

[spezimass]

Before suspend & resume the behaviour of the led-backlight pressing F1 or F2 key is adjustable.
Checking the register `/sys/class/backlight/intel_backlight/brightness` the range from 0 to 2770 can be operated in 21 steps.
After resume still the full range is triggered with the F1 to F2 keys, but here the backlight is turned off completely for all values less than 2280 and fully turned on for all values greater 2290.

Setting the brightness with `echo 2289 > /sys/class/backlight/intel_backlight/brightness` the led backlight starts to flicker in a period of approx 1sec.

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: linux-image-3.11.0-12-generic 3.11.0-12.19 [modified: boot/vmlinuz-3.11.0-12-generic]
ProcVersionSignature: Ubuntu 3.11.0-12.19-generic 3.11.3
Uname: Linux 3.11.0-12-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.12.5-0ubuntu2
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: seba 1960 F.... pulseaudio
 /dev/snd/controlC0: seba 1960 F.... pulseaudio
Date: Sat Oct 19 11:49:38 2013
EcryptfsInUse: Yes
HibernationDevice: RESUME=UUID=d22df40a-a801-4e4f-a3ba-b3246e93d6db
InstallationDate: Installed on 2013-10-17 (1 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
MachineType: Apple Inc. MacBookAir6,2
MarkForUpload: True
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.11.0-12-generic.efi.signed root=UUID=77b6a0d2-1d2f-480c-9e22-730bc9b73fed ro pcie_aspm=force i915.i915_enable_rc6=1 i915.i915_enable_fbc=1 i915.lvds_downclock=1 acpi_backlight=vendor
RelatedPackageVersions:
 linux-restricted-modules-3.11.0-12-generic N/A
 linux-backports-modules-3.11.0-12-generic N/A
 linux-firmware 1.116
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 07/12/2013
dmi.bios.vendor: Apple Inc.
dmi.bios.version: MBA61.88Z.0099.B01.1307121317
dmi.board.asset.tag: Base Board Asset Tag#
dmi.board.name: Mac-7DF21CB3ED6977E5
dmi.board.vendor: Apple Inc.
dmi.board.version: MacBookAir6,2
dmi.chassis.type: 10
dmi.chassis.vendor: Apple Inc.
dmi.chassis.version: Mac-7DF21CB3ED6977E5
dmi.modalias: dmi:bvnAppleInc.:bvrMBA61.88Z.0099.B01.1307121317:bd07/12/2013:svnAppleInc.:pnMacBookAir6,2:pvr1.0:rvnAppleInc.:rnMac-7DF21CB3ED6977E5:rvrMacBookAir6,2:cvnAppleInc.:ct10:cvrMac-7DF21CB3ED6977E5:
dmi.product.name: MacBookAir6,2
dmi.product.version: 1.0
dmi.sys.vendor: Apple Inc.

[Brad Figg (brad-figg)]

This change was made by a bot.

[penalvch (penalvch)]

spezimass, this bug was reported a while ago and there hasn't been any activity in it recently. We were wondering if this is still an issue? If so, could you please test for this with the latest development release of Ubuntu? ISO images are available from http://cdimage.ubuntu.com/daily-live/current/ .

If it remains an issue, could you please run the following command in the development release from a Terminal (Applications->Accessories->Terminal), as it will automatically gather and attach updated debug information to this report:

apport-collect -p linux <replace-with-bug-number>

Also, could you please test the latest upstream kernel available (not the daily folder) 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-v3.13-rc2

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.

[spezimass (spezimass)]

Bug still persistant

kernel-bug-exists-upstream
kernel-bug-exists-upstream-3.13.0-031300rc3-generic

[spezimass (spezimass)]

Bios updated but this did not fix the issue.

dmi.bios.date: 09/27/2013
dmi.bios.vendor: Apple Inc.
dmi.bios.version: MBA61.88Z.0099.B04.1309271229
dmi.board.asset.tag: Base Board Asset Tag#
dmi.board.vendor: Apple Inc.
dmi.board.version: MacBookAir6,2

[spezimass (spezimass)]

Christopher, I did not try a release before saucy, as the macbook uses haswell processors which seamed not to be supported on raring. The issue is also under discussion on https://bugs.freedesktop.org/show_bug.cgi?id=67454 but without much progress so far.

[spezimass (spezimass)]

found the bug report https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1197451 no booting possible for previous releases to saucy.

[spezimass (spezimass)]

done ... https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1197451/comments/72

[penalvch (penalvch)]

spezimass, please don't make people dumpster dive into other reports and comments. Please just make the actual comment in *this* report, and if you absolutely have to, post a link to the URL. So, given that the fix for bug 1197451 has been released for Saucy, could you please retest and advise, by making a full comment in this report, on if this is reproducible in Saucy?

[spezimass (spezimass)]

Retest with kernel v3.13-rc5-trusty. Bug still persists.