using "acpi_backlight=vendor" on Saucy. 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. 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 InstallationDate: Installed on 2013-10-17 (1 days ago) InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1) MachineType: Apple Inc. MacBookAir6,2 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 -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1197482 Title: After suspend/resume, screen is dark for brighness levels below 13 with i915 driver on MacBook Air 6,2 Status in “linux” package in Ubuntu: Confirmed 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. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1197482/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp