[Lenovo B470e] Backlight interface does not working
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux-lts-saucy (Ubuntu) |
Won't Fix
|
Medium
|
Unassigned | ||
linux-lts-trusty (Ubuntu) |
Confirmed
|
Medium
|
Unassigned | ||
Bug Description
Brightness Keys does not work on this system with 12.04.4.
Brightness slider in "Settings > Brightness and Lock" does not function as well.
There is two backlight interfaces under /sys/class/
lrwxrwxrwx 1 root root 0 Apr 10 05:19 ideapad -> ../../devices/
lrwxrwxrwx 1 root root 0 Apr 10 05:19 intel_backlight -> ../../devices/
Trying to modify brightness value directly in the control file, but only intel_backlight
Further investigating by trying older kernel versions,
brightness hot keys and backlight interfaces works just fine with 3.2, 3.5, 3.8 .
Verified with:
linux-image-
linux-image-
ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: linux-image-
ProcVersionSign
Uname: Linux 3.11.0-15-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version k3.11.0-15-generic.
ApportVersion: 2.0.1-0ubuntu17.6
Architecture: amd64
ArecordDevices:
**** List of CAPTURE Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: ALC272 Analog [ALC272 Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
Card hw:0 'PCH'/'HDA Intel PCH at 0x90600000 irq 44'
Mixer name : 'Intel CougarPoint HDMI'
Components : 'HDA:10ec0272,
Controls : 28
Simple ctrls : 10
Date: Thu Apr 10 05:22:31 2014
HibernationDevice: RESUME=
InstallationMedia: Ubuntu 12.04.4 LTS "Precise Pangolin" - Release amd64 (20140204)
MachineType: LENOVO HuronRiver Platform
MarkForUpload: True
ProcEnviron:
TERM=xterm
PATH=(custom, no user)
LANG=en_US.UTF-8
SHELL=/bin/bash
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=
RelatedPackageV
linux-
linux-
linux-firmware 1.79.9
SourcePackage: linux-lts-saucy
StagingDrivers: rts5139
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 02/16/2012
dmi.bios.vendor: LENOVO
dmi.bios.version: 43CN45WW
dmi.board.
dmi.board.name: Emerald Lake
dmi.board.vendor: LENOVO
dmi.board.version: FAB1
dmi.chassis.
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.
dmi.modalias: dmi:bvnLENOVO:
dmi.product.name: HuronRiver Platform
dmi.product.
dmi.sys.vendor: LENOVO
description: | updated |
Changed in linux-lts-saucy (Ubuntu): | |
status: | New → Confirmed |
Changed in linux-lts-saucy (Ubuntu): | |
importance: | Undecided → Medium |
tags: | added: blocks-hwcert-enablement |
Changed in linux-lts-saucy (Ubuntu): | |
assignee: | nobody → Jesse Sung (wenchien) |
Changed in linux-lts-saucy (Ubuntu): | |
status: | Expired → Won't Fix |
Changed in linux-lts-trusty (Ubuntu): | |
status: | New → Confirmed |
importance: | Undecided → Medium |
@Yung Shen /wiki.ubuntu. com/Kernel/ LTSEnablementSt ack, the Saucy HWE stack should already be EOL'd, should we close this bug?
According to https:/