Public bug reported: The brightness controls on this laptop with NVS 3100m work while running Nouveau or when using a text mode VT, but not while running X and using proprietary NVIDIA drivers. About 3 weeks ago it was possible to force the nvidia driver to control the backlight by adding [Option "RegistryDwords" "EnableBrightnessControl=1"] to the "Devices" section of xorg.conf . While this allowed the backlight to be controlled, the increments were inconsistent and resulted in a buzzing noise from the LED backlight. Since this did not occur while running nouveau or when switching in text VT, something was wrong.
However, adding this option to xorg.conf no longer works. I believe this is some type of regression. The ideal solution would be to apply the backlight control method used by text VTs to X, because it would work around this regression AND prevent the possibly hardware-damaging electrical issues caused by the proprietary nvidia driver's forced backlight controls (which are not enabled by default). This bad backlight behaviour has been confirmed on ThinkPad models T510 and W510 via http://www.thinkwiki.org/wiki/Category:T510 , and I mentioned it to a developer on the nvnews.net forums. ProblemType: Bug DistroRelease: Ubuntu 10.04 Package: nvidia-current 195.36.15-0ubuntu2 ProcVersionSignature: Ubuntu 2.6.32-19.28-generic 2.6.32.10+drm33.1 Uname: Linux 2.6.32-19-generic x86_64 NonfreeKernelModules: nvidia Architecture: amd64 Date: Mon Apr 12 23:48:02 2010 DkmsStatus: tp-smapi, 0.40, 2.6.32-19-generic, x86_64: installed vboxnetadp, 3.1.6, 2.6.32-19-generic, x86_64: installed vboxnetflt, 3.1.6, 2.6.32-19-generic, x86_64: installed vboxdrv, 3.1.6, 2.6.32-19-generic, x86_64: installed nvidia-current, 195.36.15, 2.6.32-19-generic, x86_64: installed EcryptfsInUse: Yes GdmLog1: Lsusb: Bus 002 Device 002: ID 8087:0020 Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 003: ID 17ef:480f Lenovo Bus 001 Device 002: ID 8087:0020 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub MachineType: LENOVO 4313CTO ProcCmdLine: BOOT_IMAGE=/bhostnamet/vmlinuz-2.6.32-19-generic rhostnamet=UUID=0b95b314-337f-49aa-86f9-6423e76e9f20 ro ProcEnviron: LANG=en_CA.utf8 SHELL=/bin/bash SourcePackage: nvidia-graphics-drivers XorgLogOld: dmi.bios.date: 02/22/2010 dmi.bios.vendor: LENOVO dmi.bios.version: 6MET49WW (1.12 ) dmi.board.name: 4313CTO dmi.board.vendor: LENOVO dmi.board.version: Not Available dmi.chassis.asset.tag: No Asset Information dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: Not Available dmi.modalias: dmi:bvnLENOVO:bvr6MET49WW(1.12):bd02/22/2010:svnLENOVO:pn4313CTO:pvrThinkPadT510:rvnLENOVO:rn4313CTO:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable: dmi.product.name: 4313CTO dmi.product.version: ThinkPad T510 dmi.sys.vendor: LENOVO system: distro: Ubuntu codename: lucid architecture: x86_64 kernel: 2.6.32-19-generic ** Affects: nvidia-graphics-drivers (Ubuntu) Importance: Undecided Status: New ** Tags: backlight lenovo nvidia proprietary t510 thinkpad vt w510 xorg -- Backlight brightness on ThinkPad T510 can only be changed in Text Mode, not X https://bugs.launchpad.net/bugs/562005 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
