Stefan Burnicki, the next step is to fully commit bisect from kernel 3.13 to 3.16 in order to identify the last good kernel commit, followed immediately by the first bad one. This will allow for a more expedited analysis of the root cause of your issue. Could you please do this following https://wiki.ubuntu.com/Kernel/KernelBisection ?
Please note, finding adjacent kernel versions is not fully commit bisecting. Thank you for your understanding. Helpful bug reporting tips: https://wiki.ubuntu.com/ReportingBugs ** Tags added: needs-bisect regression-release utopic ** Changed in: linux (Ubuntu) Status: Confirmed => Incomplete -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1454207 Title: Samsung 730U3E LCD backlight brightness control doesn't work Status in linux package in Ubuntu: Incomplete Bug description: Fn-shortcuts work and the value in /sys/class/backlight/intel_backlight/brightness changes, but is has no physical effect. Only setting /sys/class/backlight/intel_backlight/brightness to 0 turns the LCD off, changing it to any other value turns it on again. I tried to set different boot parameters in /etc/defaults/grub GRUB_CMDLINE_LINUX_DEFAULT="quiet splash video.use_native_backlight=1" GRUB_CMDLINE_LINUX_DEFAULT="quiet splash video.use_native_backlight=0" GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor" GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux acpi_backlight=vendor" GRUB_CMDLINE_LINUX_DEFAULT="quiet splash video.use_bios_initial_backlight=0" For each change, I called update-grub, restarted, and verfied the settings with /proc/cmdline. Nothing worked for me. I also tested this with the newest mainline kernel (4.1-rc2), but the bug still exists. It work with trusty and stopped working with utopic. I thought this issue would may be fixed in vivid, but it isn't. Please tell me what other information you need in order to fix this. ProblemType: Bug DistroRelease: Ubuntu 15.04 Package: linux-image-3.19.0-16-generic 3.19.0-16.16 ProcVersionSignature: Ubuntu 3.19.0-16.16-generic 3.19.3 Uname: Linux 3.19.0-16-generic x86_64 ApportVersion: 2.17.2-0ubuntu1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: stefan 1383 F.... pulseaudio CurrentDesktop: KDE Date: Tue May 12 13:08:51 2015 HibernationDevice: RESUME=UUID=34e06653-f31c-45ef-80ca-9eddcae5134f InstallationDate: Installed on 2015-03-10 (62 days ago) InstallationMedia: Kubuntu-Plasma-5 14.10 "Utopic Unicorn" - Release amd64 (20141022) MachineType: SAMSUNG ELECTRONICS CO., LTD. 730U3E/740U3E ProcFB: 0 inteldrmfb 1 radeondrmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.19.0-16-generic root=/dev/mapper/kubuntu--plasma--5--vg-root ro quiet splash video.use_bios_initial_backlight=0 RelatedPackageVersions: linux-restricted-modules-3.19.0-16-generic N/A linux-backports-modules-3.19.0-16-generic N/A linux-firmware 1.143 SourcePackage: linux UpgradeStatus: Upgraded to vivid on 2015-04-26 (16 days ago) dmi.bios.date: 05/30/2013 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: P05ABW.060.130530.dg dmi.board.asset.tag: No Asset Tag dmi.board.name: NP730U3E-S03DE dmi.board.vendor: SAMSUNG ELECTRONICS CO., LTD. dmi.board.version: SEC_SW_REVISION_1234567890ABCD dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 9 dmi.chassis.vendor: SAMSUNG ELECTRONICS CO., LTD. dmi.chassis.version: N/A dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrP05ABW.060.130530.dg:bd05/30/2013:svnSAMSUNGELECTRONICSCO.,LTD.:pn730U3E/740U3E:pvrP05ABW:rvnSAMSUNGELECTRONICSCO.,LTD.:rnNP730U3E-S03DE:rvrSEC_SW_REVISION_1234567890ABCD:cvnSAMSUNGELECTRONICSCO.,LTD.:ct9:cvrN/A: dmi.product.name: 730U3E/740U3E dmi.product.version: P05ABW dmi.sys.vendor: SAMSUNG ELECTRONICS CO., LTD. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1454207/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
