Public bug reported: Using a Lenovo Ideapad u450p and Ubuntu Maverick(10.10), controlling the display brightness does work rather unexpectedly.
Expected: Keyboard keys change the brightness, where fn+down should decrease it, and fn+up should increase it. Maybe a nice applet showing what brightness is set. But, observed: The brightness alternates between very bright and very low. The applet shows up(in kde). To check whether this was a kde issue i used the command line, where the behavior is similar. r...@rawls:/proc/acpi/video/VGA/LCD# cat brightness levels: 0 10 20 30 40 50 60 70 80 90 100 current: 50 and setting works with for example echo 70 > brightness which results in 80: pretty dark 0,20,40,60,100: slightly brighter, but still rather dark 10,30,50,70,90: pretty bright which is not what one would,at least naively, expect. I tried some settings like 91, giving -bash: echo: write error: Invalid argument possibly related bugs might be - https://bugs.launchpad.net/ubuntu/+source/linux/+bug/571421 "brightness hotkeys not functional on Lenovo Ideapad u450p", though the keys work fine for me - https://bugs.launchpad.net/linux/+bug/513921 "hotkeys adjust display brightness non-monotonically on new Asus pinetrail netbooks (1001P, 1005P, 1005PE)" I tried the workaround from bug 513921, but after adding acpi_osi=linux and acpi_backlight=vendor I could not set the display brightness at all any more. I hope ubuntu-bug attached the necessary information this is filed in the right place. ProblemType: Bug DistroRelease: Ubuntu 10.10 Package: linux-image-2.6.35-22-generic 2.6.35-22.35 Regression: No Reproducible: Yes ProcVersionSignature: Ubuntu 2.6.35-22.35-generic 2.6.35.4 Uname: Linux 2.6.35-22-generic x86_64 AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23. Architecture: amd64 ArecordDevices: **** List of CAPTURE Hardware Devices **** card 0: Intel [HDA Intel], device 0: ALC272 Analog [ALC272 Analog] Subdevices: 1/1 Subdevice #0: subdevice #0 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: goelzera 7763 F.... pulseaudio Card0.Amixer.info: Card hw:0 'Intel'/'HDA Intel at 0xf0400000 irq 46' Mixer name : 'Realtek ALC272' Components : 'HDA:10ec0272,17aac006,00100001' Controls : 17 Simple ctrls : 10 Card1.Amixer.info: Card hw:1 'HDMI'/'HDA ATI HDMI at 0xf0210000 irq 47' Mixer name : 'ATI R6xx HDMI' Components : 'HDA:1002aa01,00aa0100,00100100' Controls : 4 Simple ctrls : 1 Card1.Amixer.values: Simple mixer control 'IEC958',0 Capabilities: pswitch pswitch-joined penum Playback channels: Mono Mono: Playback [off] Date: Fri Nov 19 00:52:44 2010 HibernationDevice: RESUME=UUID=7a4abe7d-4147-48d0-8057-b1f964dc963b InstallationMedia: Kubuntu 10.10 "Maverick Meerkat" - Release Candidate amd64 (20100928.3) MachineType: LENOVO 3389 ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.35-22-generic root=UUID=7965020f-a640-4958-8bea-09eb9aaa31a3 ro ProcEnviron: LANGUAGE= PATH=(custom, user) LANG=en_US.UTF-8 SHELL=/bin/bash RelatedPackageVersions: linux-firmware 1.38 SourcePackage: linux WifiSyslog: dmi.bios.date: 01/20/2010 dmi.bios.vendor: LENOVO dmi.bios.version: 22CN35WW(V2.02) dmi.board.name: NITU1 dmi.board.vendor: LENOVO dmi.board.version: REFERENCE dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: No Enclosure dmi.chassis.version: N/A dmi.modalias: dmi:bvnLENOVO:bvr22CN35WW(V2.02):bd01/20/2010:svnLENOVO:pn3389:pvrLenovoIdeaPadU450p:rvnLENOVO:rnNITU1:rvrREFERENCE:cvnNoEnclosure:ct10:cvrN/A: dmi.product.name: 3389 dmi.product.version: Lenovo IdeaPad U450p dmi.sys.vendor: LENOVO ** Affects: linux (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug kernel-power maverick needs-upstream-testing resume suspend -- Brightness control on Lenovo Ideapad u450p behaves non-monotonically https://bugs.launchpad.net/bugs/677274 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
