kernel-packages team mailing list archive

[Stefan Burnicki <stefan.burnicki@xxxxxxxxxxxx>]

Public bug reported:

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.

** Affects: linux (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: amd64 apport-bug vivid

** Summary changed:

- LCD backlight brightness control doesn't work
+ Samsung 730U3E LCD backlight brightness control doesn't work

-- 
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:
  New

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