kernel-packages team mailing list archive

[Sean V Kelley <seanvk@xxxxxxxxx>]

There is a work around for the backlight issue.

reference:  https://bugs.freedesktop.org/show_bug.cgi?id=67454

> 
> To get it running you need to download and build the driver:
> 
> # git clone https://github.com/patjak/mba6x_bl
> # cd mba6x_bl/ && make && make install
> 
> Make sure the module is loaded at boot time. E.g add "mba6x_bl" to
> /etc/modules
> You also need to configure i915 to hand over the backlight control to
> mba6x_bl. I added this to my /etc/X11/xorg.conf:
> 
> Section "Device"
>         Identifier      "Intel Graphics"
>         Driver          "intel"
>         Option          "Backlight"     "mba6x_backlight"
> EndSection
> 
> Now reboot and you should have working brightness even after suspend/resume.
> Unloading the module (modprobe -r mba6x_bl) will restore the backlight to
> whatever state we had when loading it.

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https://bugs.launchpad.net/bugs/1197482

Title:
  8086:0a26 [MacBook Air 6,2] After suspend/resume, screen is dark for
  brighness levels below 13 with i915 driver

Status in “linux” package in Ubuntu:
  Incomplete

Bug description:
  After installing Raring on my 2013 MacBook Air 6,2, I find that sometimes when resuming from suspend, the screen is dark. I have tracked this down to the i915 driver, where the screen brightness can be adjusted between levels 0-15. This works correctly after boot, with 0 being dark and 15 the brightest. Sometimes after suspend/resume, the screen is equally dark between levels 0-12, and seems to be equally bright for levels 13-15 (brightest). I say sometimes, because it's not every time. It _might_ be after the second or third suspend/resume, but I'm not yet sure how to repeat it. When this happens, I have to kill lightum, the backlight/keyboard monitoring daemon, and manually set the brightness using the sys filesystem:
  echo '15' | sudo tee /sys/devices/pci0000\:00/0000\:00\:02.0/backlight/acpi_video0/brightness

  ProblemType: Bug
  DistroRelease: Ubuntu 13.04
  Package: linux-image-3.8.0-25-generic 3.8.0-25.37
  ProcVersionSignature: Ubuntu 3.8.0-25.37-generic 3.8.13
  Uname: Linux 3.8.0-25-generic x86_64
  NonfreeKernelModules: wl
  ApportVersion: 2.9.2-0ubuntu8.1
  Architecture: amd64
  AudioDevicesInUse:
   USER        PID ACCESS COMMAND
   /dev/snd/controlC0:  linus      1939 F.... pulseaudio
  CRDA:
   country SE:
    (2402 - 2482 @ 40), (N/A, 20)
    (5170 - 5250 @ 40), (N/A, 20)
    (5250 - 5330 @ 40), (N/A, 20), DFS
    (5490 - 5710 @ 40), (N/A, 27), DFS
  Date: Wed Jul  3 19:23:53 2013
  HibernationDevice:
   RESUME=/dev/mapper/cryptswap1
   #RESUME=UUID=7625120b-1951-4a58-8da6-1c47db358631
  MachineType: Apple Inc. MacBookAir6,2
  MarkForUpload: True
  ProcFB: 0 inteldrmfb
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.8.0-25-generic root=UUID=2f08800d-d161-46e7-87b6-0f88e86890af ro i915.i915_enable_rc6=3 libata.force=1:noncq resume=/dev/sda4 quiet splash vt.handoff=7
  RelatedPackageVersions:
   linux-restricted-modules-3.8.0-25-generic N/A
   linux-backports-modules-3.8.0-25-generic  N/A
   linux-firmware                            1.106
  SourcePackage: linux
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/24/2013
  dmi.bios.vendor: Apple Inc.
  dmi.bios.version: MBA61.88Z.0099.B00.1305241529
  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.B00.1305241529:bd05/24/2013: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.
  --- 
  ApportVersion: 2.12.7-0ubuntu1
  Architecture: amd64
  AudioDevicesInUse:
   USER        PID ACCESS COMMAND
   /dev/snd/controlC1:  ubuntu     2716 F.... pulseaudio
                        ubuntu     5277 F.... pulseaudio
   /dev/snd/controlC0:  ubuntu     2716 F.... pulseaudio
                        ubuntu     5277 F.... pulseaudio
  CasperVersion: 1.336ubuntu1
  CurrentDesktop: Unity
  DistroRelease: Ubuntu 14.04
  LiveMediaBuild: Ubuntu 14.04 LTS "Trusty Tahr" - Alpha amd64+mac (20131203)
  MachineType: Apple Inc. MacBookAir6,2
  MarkForUpload: True
  NonfreeKernelModules: wl
  Package: linux (not installed)
  ProcFB: 0 inteldrmfb
  ProcKernelCmdLine: file=/cdrom/preseed/username.seed boot=casper initrd=/casper/initrd.lz quiet splash -- maybe-ubiquity
  ProcVersionSignature: Ubuntu 3.12.0-5.13-generic 3.12.2
  RelatedPackageVersions:
   linux-restricted-modules-3.12.0-5-generic N/A
   linux-backports-modules-3.12.0-5-generic  N/A
   linux-firmware                            1.117
  Tags:  trusty
  Uname: Linux 3.12.0-5-generic x86_64
  UpgradeStatus: No upgrade log present (probably fresh install)
  UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
  WifiSyslog:
   
  dmi.bios.date: 05/24/2013
  dmi.bios.vendor: Apple Inc.
  dmi.bios.version: MBA61.88Z.0099.B00.1305241529
  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.B00.1305241529:bd05/24/2013: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.

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