on thinkpad-acpi devices, brightness setting ommits most steps
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Fix Released
|
Medium
|
Unassigned | ||
Precise |
Fix Released
|
Undecided
|
Alex Hung | ||
Quantal |
Fix Released
|
Undecided
|
Unassigned | ||
Raring |
Fix Released
|
Medium
|
Unassigned |
Bug Description
Brightness changes in very rough steps on some Machines, but only when there is the gpm-OSD appearing showing the brightness setting. So the bug appears not when the session showed is locked, but in an active session or on the login screen the bug appears.
On my machine (thinkpad X60) brightness changes with two steps between min and max - these steps are different depending on wether you go up or down hough. So you can hit 6 settings. I think the firmware is capable I think 8, surely indepent on wether set higher or lower.
This is found on an X60 Tablet, an Lenovo Netbook (sorry, not sure which device exactly) and an X201 Tablet. This leads me to believe this is an issue with the thinkpad-acpi kernel module, which has an proprietary interface for the screen brightness.
ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: gnome-power-manager 2.32.0-2ubuntu2
ProcVersionSign
Uname: Linux 3.0-1-generic x86_64
Architecture: amd64
Date: Sun Sep 4 21:28:58 2011
GnomeSessionIdl
GnomeSessionInh
GnomeSessionSus
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1)
MachineType: LENOVO 6363C7G
ProcEnviron:
LANGUAGE=de_CH:en
LANG=de_CH.UTF-8
SHELL=/bin/bash
ProcKernelCmdLine: root=/dev/
SourcePackage: gnome-power-manager
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 01/23/2008
dmi.bios.vendor: LENOVO
dmi.bios.version: 7JET27WW (1.12 )
dmi.board.name: 6363C7G
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.
dmi.modalias: dmi:bvnLENOVO:
dmi.product.name: 6363C7G
dmi.product.
dmi.sys.vendor: LENOVO
Related branches
CVE References
affects: | gnome-power-manager (Ubuntu) → linux (Ubuntu) |
Changed in linux (Ubuntu): | |
assignee: | nobody → Alex Hung (alexhung) |
Changed in linux (Ubuntu): | |
milestone: | none → precise-updates |
Changed in linux (Ubuntu): | |
importance: | Undecided → Medium |
tags: | added: precise quantal |
Changed in linux (Ubuntu): | |
status: | Won't Fix → Confirmed |
Changed in linux (Ubuntu Precise): | |
assignee: | nobody → Alex Hung (alexhung) |
status: | New → Fix Committed |
Changed in linux (Ubuntu Quantal): | |
status: | New → Fix Released |
Changed in linux (Ubuntu Raring): | |
status: | Confirmed → Fix Released |
assignee: | Alex Hung (alexhung) → nobody |
Agree this is a bug, the problem is exactly the same on my IBM T60 2623-D6U, Ubuntu 12.04. It is possible to have "single step" brightness using 1) kernel parameter acpi_backlight= vendor and 2) thinkpad_acpi module parameter brightness_ enable= 0. But in this case OSD brighness change notification desappears.