[Dell Latitude 6430u] Brightness keys do not work

[Jeff Lane ]

Running 12.04.2 on the system and the brightness keys do not work. The keys are a combination of Fn and Up or Down arrow.

On attempting to use the keys, there is no effect on screen brightness, nor is there the brightness indicator.

However, I am able to control brightness using the Brightness settings from "System Settings"

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: linux-image-3.5.0-23-generic 3.5.0-23.35~precise1
ProcVersionSignature: Ubuntu 3.5.0-23.35~precise1-generic 3.5.7.2
Uname: Linux 3.5.0-23-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.25.
ApportVersion: 2.0.1-0ubuntu17.1
Architecture: amd64
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: PCH [HDA Intel PCH], device 0: STAC92xx Analog [STAC92xx Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: ubuntu 1407 F.... pulseaudio
CRDA:
 country TW:
  (2402 - 2472 @ 40), (3, 27)
  (5270 - 5330 @ 40), (3, 17), DFS
  (5735 - 5815 @ 40), (3, 30)
Card0.Amixer.info:
 Card hw:0 'PCH'/'HDA Intel PCH at 0xf7e30000 irq 48'
   Mixer name : 'Intel PantherPoint HDMI'
   Components : 'HDA:111d76df,10280584,00100203 HDA:80862806,80860101,00100000'
   Controls : 23
   Simple ctrls : 10
Date: Mon Mar 4 02:25:42 2013
HibernationDevice: RESUME=UUID=c0470f10-8436-437b-8009-ba2be8ecb392
InstallationMedia: Ubuntu 12.04.2 LTS "Precise Pangolin" - Release amd64 (20130213)
MachineType: Dell Inc. Latitude 6430U
MarkForUpload: True
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.5.0-23-generic root=UUID=4c3d4b80-eff7-43f9-bf80-3904f2788102 ro quiet splash initcall_debug vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.5.0-23-generic N/A
 linux-backports-modules-3.5.0-23-generic N/A
 linux-firmware 1.79.1
RfKill:
 0: phy0: Wireless LAN
  Soft blocked: no
  Hard blocked: no
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 08/31/2012
dmi.bios.vendor: Dell Inc.
dmi.bios.version: X28
dmi.board.name: 0V4GYG
dmi.board.vendor: Dell Inc.
dmi.board.version: X01
dmi.chassis.type: 9
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrX28:bd08/31/2012:svnDellInc.:pnLatitude6430U:pvr01:rvnDellInc.:rn0V4GYG:rvrX01:cvnDellInc.:ct9:cvr:
dmi.product.name: Latitude 6430U
dmi.product.version: 01
dmi.sys.vendor: Dell Inc.

[Brad Figg (brad-figg)]

This change was made by a bot.

[Anthony Wong (anthonywong)]

Had this issue during platform enablement, acpi_listen did not report anything when this issue happened, so it's BIOS is suspicious. Could you update the BIOS to the latest one that's released on Dell website? http://www.dell.com/support/drivers/us/en/04/DriverDetails?driverId=9FGF3

[Jeff Lane  (bladernr)]

File Format: Windows/DOS
File Name: 6430UA04.exe
Description: This file format consists of a BIOS executable file. The Universal (Windows/MS DOS) format can be used to install from Windows XP, Windows 2000, NT, Windows 9X, Windows ME or a MS DOS environment.

Nope, I have no means of doing so. I don't have anything with Windows on it right now.

[James M. Leddy (jm-leddy)]

Hi Jeff,

We issued a certificate for 12.04, even though the brightness hotkey was not working at that time. Why did we make an exception then but not for N+1?

[Po-Hsu Lin (cypressyew)]

Hello James,
brightness hotkey is in our gerylist, therefore it won't block the certificate.

Further investigated this issue, I found out that:

1. Tested with $sudo showkey -s, the key press is not detected at all.
2. Tested with a external keyboard that comes with brightness key, it works.
3. Tested with 12.04.2 LiveUSB, the brightness key works as expected.

And some interesting results -
The brightness key will work when the system was booted with:
a. a specific brand 2GB FAT USB flash drive (tested with other USB, only this brand here will work)
b. a USB 3D sound controller
c. a USB cable with nothing connected (yes, nothing, just a cable)

Only cold plug will work.
And if you unplug these device, the brightness key still work until you reboot/suspend it.

Brightness key still not working when booted with these device plugged.
USB keyboard/mouse, USB keyboard/mouse receiver, FAT USB flash drive from 4GB ~ 16GB, SD Card.

At last, it seems that this issue could be fixed by updating the system.

[penalvch (penalvch)]

Jeff Lane, other folks with Dell laptops have been able to update the BIOS utilizing https://help.ubuntu.com/community/BiosUpdate . As per http://www.dell.com/support/drivers/us/en/19/product/latitude-6430u-ultrabook an update is available for your BIOS (A06). If you update to this following does it change anything? If it doesn't, could you please both specify what happened, and provide the output of the following terminal command:
sudo dmidecode -s bios-version && sudo dmidecode -s bios-release-date

Thank you for your understanding.

[Po-Hsu Lin (cypressyew)]

As this issue can be fixed by updating the system, I will mark this bug as "Fix-released"
If anyone still experiencing this, please feel free to open a new bug.