Control of screen backlight is broken with a default clean install of Ubuntu 15.04 on my Samsung Series 7 Laptop (NP770Z5E). Setting kernal parameter acpi_backlight=vendor fixes the issue after two reboots. Debugging information attached as per - https://wiki.ubuntu.com/Kernel/Debugging/Backlight
ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: linux-image-3.19.0-25-generic 3.19.0-25.26
ProcVersionSignature: Ubuntu 3.19.0-25.26-generic 3.19.8-ckt2
Uname: Linux 3.19.0-25-generic x86_64
ApportVersion: 2.17.2-0ubuntu1.2
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: mark 1699 F.... pulseaudio
Date: Sat Aug 15 21:36:20 2015
HibernationDevice: RESUME=UUID=c4899b44-3e19-4e62-921d-cf0a1cef97ec
InstallationDate: Installed on 2015-08-12 (3 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422)
MachineType: SAMSUNG ELECTRONICS CO., LTD. 770Z5E/780Z5E
ProcFB:
0 inteldrmfb
1 radeondrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.19.0-25-generic root=UUID=5a02817b-1f9b-4abc-93a3-b10d5d9278ed ro quiet splash acpi_backlight=vendor vt.handoff=7
PulseList:
Error: command ['pacmd', 'list'] failed with exit code 1: Home directory not accessible: Permission denied
No PulseAudio daemon running, or not running as session daemon.
RelatedPackageVersions:
linux-restricted-modules-3.19.0-25-generic N/A
linux-backports-modules-3.19.0-25-generic N/A
linux-firmware 1.143.3
SourcePackage: linux
UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 09/05/2013
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: P05ABU.142.130905.SK
dmi.board.asset.tag: No Asset Tag
dmi.board.name: NP770Z5E-S02UK
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.:bvrP05ABU.142.130905.SK:bd09/05/2013:svnSAMSUNGELECTRONICSCO.,LTD.:pn770Z5E/780Z5E:pvrP05ABU:rvnSAMSUNGELECTRONICSCO.,LTD.:rnNP770Z5E-S02UK:rvrSEC_SW_REVISION_1234567890ABCD:cvnSAMSUNGELECTRONICSCO.,LTD.:ct9:cvrN/A:
dmi.product.name: 770Z5E/780Z5E
dmi.product.version: P05ABU
dmi.sys.vendor: SAMSUNG ELECTRONICS CO., LTD.
Control of screen backlight is broken with a default clean install of Ubuntu 15.04 on my Samsung Series 7 Laptop (NP770Z5E). Setting kernal parameter acpi_backlight= vendor fixes the issue after two reboots. Debugging information attached as per - https:/ /wiki.ubuntu. com/Kernel/ Debugging/ Backlight
ProblemType: Bug 3.19.0- 25-generic 3.19.0-25.26 ature: Ubuntu 3.19.0- 25.26-generic 3.19.8-ckt2 controlC0: mark 1699 F.... pulseaudio UUID=c4899b44- 3e19-4e62- 921d-cf0a1cef97 ec /boot/vmlinuz- 3.19.0- 25-generic root=UUID= 5a02817b- 1f9b-4abc- 93a3-b10d5d9278 ed ro quiet splash acpi_backlight= vendor vt.handoff=7 ersions: restricted- modules- 3.19.0- 25-generic N/A backports- modules- 3.19.0- 25-generic N/A 142.130905. SK asset.tag: No Asset Tag REVISION_ 1234567890ABCD asset.tag: No Asset Tag version: N/A MegatrendsInc. :bvrP05ABU. 142.130905. SK:bd09/ 05/2013: svnSAMSUNGELECT RONICSCO. ,LTD.:pn770Z5E/ 780Z5E: pvrP05ABU: rvnSAMSUNGELECT RONICSCO. ,LTD.:rnNP770Z5 E-S02UK: rvrSEC_ SW_REVISION_ 1234567890ABCD: cvnSAMSUNGELECT RONICSCO. ,LTD.:ct9: cvrN/A: version: P05ABU
DistroRelease: Ubuntu 15.04
Package: linux-image-
ProcVersionSign
Uname: Linux 3.19.0-25-generic x86_64
ApportVersion: 2.17.2-0ubuntu1.2
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/
Date: Sat Aug 15 21:36:20 2015
HibernationDevice: RESUME=
InstallationDate: Installed on 2015-08-12 (3 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422)
MachineType: SAMSUNG ELECTRONICS CO., LTD. 770Z5E/780Z5E
ProcFB:
0 inteldrmfb
1 radeondrmfb
ProcKernelCmdLine: BOOT_IMAGE=
PulseList:
Error: command ['pacmd', 'list'] failed with exit code 1: Home directory not accessible: Permission denied
No PulseAudio daemon running, or not running as session daemon.
RelatedPackageV
linux-
linux-
linux-firmware 1.143.3
SourcePackage: linux
UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 09/05/2013
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: P05ABU.
dmi.board.
dmi.board.name: NP770Z5E-S02UK
dmi.board.vendor: SAMSUNG ELECTRONICS CO., LTD.
dmi.board.version: SEC_SW_
dmi.chassis.
dmi.chassis.type: 9
dmi.chassis.vendor: SAMSUNG ELECTRONICS CO., LTD.
dmi.chassis.
dmi.modalias: dmi:bvnAmerican
dmi.product.name: 770Z5E/780Z5E
dmi.product.
dmi.sys.vendor: SAMSUNG ELECTRONICS CO., LTD.