@Fortunato: Do your patches have any NC10 specific fixes? ** Description changed:
This is a continuation from bug 810093 but I'm using Samsung NC10. The backlight of the laptop often starts flickering (switching very fast - between 2 brightness levels) when gnome tries to reduce the screen + between darkest and brightest) when gnome tries to reduce the screen brightness (automatically after some time) to save power. This bug is caused by the new samsung_laptop kernel module which was introduced in kernel 2.6.39. I've found some documentation for it at - github [1]. If the module is enabled, the flickering quite soon after - desktop load and can be stopped by changing the baclight brigtness. - However, the only available modes are 0%, 10%(estimate) and 100%. The - two lowest values are too dark for my eyes and the full backlight uses - too much battery power. + github [1]. If the module is enabled, the flickering starts quite soon + after desktop load and can be stopped by changing the baclight + brigtness. However, the only available modes are 0%, 10%(estimate) and + 100%. The two lowest values are too dark for my eyes and the full + backlight uses too much battery power. The main difference from bug 810093 is that this issue doesn't occur on every boot but maybe on 80% of boots. WORKAROUND: Disable the kernel module by adding: blacklist samsung_laptop to : /etc/modprobe.d/blacklist.conf OR use Voria's patch/PPA (links in the above mentioned bug). [1] https://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=2d70b73ae5b85c9d13f5dfbb8fc4fd5edae633dc ProblemType: Bug DistroRelease: Ubuntu 11.10 Package: linux-image-3.0.0-15-generic 3.0.0-15.25 ProcVersionSignature: Ubuntu 3.0.0-15.25-generic 3.0.13 Uname: Linux 3.0.0-15-generic i686 AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24. AplayDevices: **** List of PLAYBACK Hardware Devices **** card 0: Intel [HDA Intel], device 0: ALC272 Analog [ALC272 Analog] Subdevices: 1/1 Subdevice #0: subdevice #0 ApportVersion: 1.23-0ubuntu4 Architecture: i386 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: user 1581 F.... pulseaudio CRDA: Error: [Errno 2] Tiedostoa tai hakemistoa ei ole Card0.Amixer.info: Card hw:0 'Intel'/'HDA Intel at 0xf0340000 irq 43' Mixer name : 'Realtek ALC272' Components : 'HDA:10ec0272,144dca00,00100001' Controls : 19 Simple ctrls : 11 Date: Sat Jan 21 18:35:12 2012 EcryptfsInUse: Yes HibernationDevice: RESUME=UUID=77010f3d-b94c-4718-8f0c-0324ea5ad852 InstallationMedia: Ubuntu-Netbook-Remix 9.10 "Karmic Koala" - Release i386 (20091028.4) MachineType: SAMSUNG ELECTRONICS CO., LTD. NC10 ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.0.0-15-generic root=UUID=af51795b-87a7-4268-b370-05a38dffd4b6 ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-3.0.0-15-generic N/A linux-backports-modules-3.0.0-15-generic N/A linux-firmware 1.60 SourcePackage: linux UpgradeStatus: Upgraded to oneiric on 2011-10-01 (112 days ago) dmi.bios.date: 09/08/2009 dmi.bios.vendor: Phoenix Technologies Ltd. dmi.bios.version: 11CA.M015.20090908.RHU dmi.board.name: NC10 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.:bvr11CA.M015.20090908.RHU:bd09/08/2009:svnSAMSUNGELECTRONICSCO.,LTD.:pnNC10:pvrNotApplicable:rvnSAMSUNGELECTRONICSCO.,LTD.:rnNC10:rvrNotApplicable:cvnSAMSUNGELECTRONICSCO.,LTD.:ct10:cvrN/A: dmi.product.name: NC10 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/919773 Title: The new (2.6.39+) samsung_laptop kernel module causes serious backlight flickering - makes the desktop unusable - part 2 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/919773/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
