[MacBook Pro 8,2] Unable to adjust display brightness
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Fix Released
|
Medium
|
Seth Forshee |
Bug Description
This machine supports the standard ACPI backlight interface, but using it has no effect on the screen brightness. The only known way to adjust screen brightness on this machine is via the gmux device, but this is not currently supported under Linux. The details of the gmux backlight interface are known, so it's a matter of getting driver support into the kernel.
ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: linux-image-
ProcVersionSign
Uname: Linux 3.2.0-12-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
ApportVersion: 1.91-0ubuntu1
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/
/dev/snd/
Card0.Amixer.info:
Card hw:0 'PCH'/'HDA Intel PCH at 0xb0900000 irq 47'
Mixer name : 'Cirrus Logic CS4206'
Components : 'HDA:10134206,
Controls : 24
Simple ctrls : 10
Card1.Amixer.info:
Card hw:1 'Generic'/'HD-Audio Generic at 0xb0840000 irq 48'
Mixer name : 'ATI R6xx HDMI'
Components : 'HDA:1002aa01,
Controls : 6
Simple ctrls : 1
Card1.Amixer.
Simple mixer control 'IEC958',0
Capabilities: pswitch pswitch-joined penum
Playback channels: Mono
Mono: Playback [on]
Date: Thu Feb 2 09:55:21 2012
HibernationDevice: RESUME=
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha amd64+mac (20111208)
MachineType: Apple Inc. MacBookPro8,2
ProcEnviron:
PATH=(custom, no user)
LANG=en_US.UTF-8
SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=
RelatedPackageV
linux-
linux-
linux-firmware 1.68
SourcePackage: linux
StagingDrivers: mei
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 09/28/11
dmi.bios.vendor: Apple Inc.
dmi.bios.version: MBP81.88Z.
dmi.board.
dmi.board.name: Mac-94245A3940C
dmi.board.vendor: Apple Inc.
dmi.board.version: MacBookPro8,2
dmi.chassis.type: 10
dmi.chassis.vendor: Apple Inc.
dmi.chassis.
dmi.modalias: dmi:bvnAppleInc
dmi.product.name: MacBookPro8,2
dmi.product.
dmi.sys.vendor: Apple Inc.
CVE References
Changed in linux (Ubuntu): | |
status: | New → Confirmed |
Changed in linux (Ubuntu): | |
status: | Confirmed → In Progress |
I've got a patch adding support for gmux backlight control to the apple_bl driver and am currently working to get it tested on a variety of Apple machines. So far the results are positive.