waldemar.yan: I'm pretty sure that something is wrong with your workaround. This shouldn't work. By unloading the samsung-laptop module you can't change the backlight without direct hw access. You must have loaded some (other none default?) module for this. Please post your lsmod output.
For a real workaround use vorias ppa #26. It contains a real fix, that still isn't in kernel. btw: you can blacklist a module, instead of unloading it on boot... ** Description changed: + *** Workaround in #26 *** + (A patched kernel module. Please test) + Original bug report: + I have a Samsung N220 plus. The backlight of the laptop often starts flickering (switching very fast between 2 brightness levels) when gnome tries to reduce the screen brightness (automatically after some time) to save power. This problem also occurs if you press more and less screen brightness at the same time. I think it could be a problem with the sabi Bios interaction (samsung-laptop.c), because "linux on my samsung" also had this Problem with theier samsung-backlight module: http://www.voria.org/forum/viewtopic.php?t=625&p=5148 and they solved it by interfacing the backlight via pci. I tried to enable debug modus of samsung-laptop module, but I didn't get any more output on error. Dmesg only says (a lot of times): ACPI: Failed to switch the brightness I'll provide more informations if needed. ProblemType: Bug DistroRelease: Ubuntu 11.10 Package: linux-image-3.0.0-5-generic 3.0.0-5.6 ProcVersionSignature: Ubuntu 3.0.0-5.6-generic 3.0.0-rc7 Uname: Linux 3.0.0-5-generic i686 NonfreeKernelModules: wl AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24. AplayDevices: - **** List of PLAYBACK Hardware Devices **** - card 0: Intel [HDA Intel], device 0: ALC269 Analog [ALC269 Analog] - Subdevices: 1/1 - Subdevice #0: subdevice #0 + **** List of PLAYBACK Hardware Devices **** + card 0: Intel [HDA Intel], device 0: ALC269 Analog [ALC269 Analog] + Subdevices: 1/1 + Subdevice #0: subdevice #0 Architecture: i386 ArecordDevices: - **** List of CAPTURE Hardware Devices **** - card 0: Intel [HDA Intel], device 0: ALC269 Analog [ALC269 Analog] - Subdevices: 1/1 - Subdevice #0: subdevice #0 + **** List of CAPTURE Hardware Devices **** + card 0: Intel [HDA Intel], device 0: ALC269 Analog [ALC269 Analog] + Subdevices: 1/1 + Subdevice #0: subdevice #0 AudioDevicesInUse: - USER PID ACCESS COMMAND - /dev/snd/controlC0: flexxxv 1405 F.... pulseaudio + USER PID ACCESS COMMAND + /dev/snd/controlC0: flexxxv 1405 F.... pulseaudio CRDA: Error: [Errno 2] Datei oder Verzeichnis nicht gefunden Card0.Amixer.info: - Card hw:0 'Intel'/'HDA Intel at 0xf0400000 irq 47' - Mixer name : 'Realtek ALC269' - Components : 'HDA:10ec0269,144dc072,00100004' - Controls : 14 - Simple ctrls : 9 + Card hw:0 'Intel'/'HDA Intel at 0xf0400000 irq 47' + Mixer name : 'Realtek ALC269' + Components : 'HDA:10ec0269,144dc072,00100004' + Controls : 14 + Simple ctrls : 9 Date: Wed Jul 13 20:56:28 2011 HibernationDevice: RESUME=UUID=9f00b9b2-337b-4462-8157-50d16690f634 InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Alpha i386 (20110705.1) MachineType: SAMSUNG ELECTRONICS CO., LTD. N150P/N210P/N220P ProcEnviron: - LANGUAGE=de:en - PATH=(custom, user) - LANG=de_DE.UTF-8 - LC_MESSAGES=de_DE.UTF-8 - SHELL=/bin/bash + LANGUAGE=de:en + PATH=(custom, user) + LANG=de_DE.UTF-8 + LC_MESSAGES=de_DE.UTF-8 + SHELL=/bin/bash ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.0.0-5-generic root=UUID=1f2007e5-9b44-4cb5-a64a-4c2bf8dbda42 ro quiet splash vt.handoff=7 RelatedPackageVersions: - linux-restricted-modules-3.0.0-5-generic N/A - linux-backports-modules-3.0.0-5-generic N/A - linux-firmware 1.56 + linux-restricted-modules-3.0.0-5-generic N/A + linux-backports-modules-3.0.0-5-generic N/A + linux-firmware 1.56 SourcePackage: linux StagingDrivers: brcmsmac brcmutil UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 04/30/2010 dmi.bios.vendor: Phoenix Technologies Ltd. dmi.bios.version: 01KY.M008.20100430.RHU dmi.board.asset.tag: SAMSUNG dmi.board.name: N150P/N210P/N220P dmi.board.vendor: SAMSUNG ELECTRONICS CO., LTD. dmi.board.version: Not Applicable dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: SAMSUNG ELECTRONICS CO., LTD. dmi.chassis.version: N/A dmi.modalias: dmi:bvnPhoenixTechnologiesLtd.:bvr01KY.M008.20100430.RHU:bd04/30/2010:svnSAMSUNGELECTRONICSCO.,LTD.:pnN150P/N210P/N220P:pvrNotApplicable:rvnSAMSUNGELECTRONICSCO.,LTD.:rnN150P/N210P/N220P:rvrNotApplicable:cvnSAMSUNGELECTRONICSCO.,LTD.:ct10:cvrN/A: dmi.product.name: N150P/N210P/N220P dmi.product.version: Not Applicable dmi.sys.vendor: SAMSUNG ELECTRONICS CO., LTD. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/810093 Title: The new (2.6.39+) samsung_laptop kernel module causes serious backlight flickering - makes the desktop unusable To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/810093/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
