[Toshiba Tecra R850-19Z PT525E] Screen brightness not changable via applet or hotkeys in Ubuntu 12.04

Bug #1178205 reported by Jens on 2013-05-09
This bug affects 2 people
Affects Status Importance Assigned to Milestone
linux (Ubuntu)

Bug Description

By default the screen is very dark and almost unreadable. The Fn+F6/7 hotkeys show the brightness applet but don't change the brightness. Attached info according to https://wiki.ubuntu.com/Kernel/Debugging/Backlight below.

WORKAROUND: acpi_backlight=vendor

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: linux-image-3.2.0-41-generic-pae 3.2.0-41.66
ProcVersionSignature: Ubuntu 3.2.0-41.66-generic-pae 3.2.42
Uname: Linux 3.2.0-41-generic-pae i686
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
ApportVersion: 2.0.1-0ubuntu17.2
Architecture: i386
 **** List of CAPTURE Hardware Devices ****
 card 0: PCH [HDA Intel PCH], device 0: ALC269VB Analog [ALC269VB Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
 /dev/snd/controlC0: ubuntu 1655 F.... pulseaudio
 Card hw:0 'PCH'/'HDA Intel PCH at 0xc4820000 irq 50'
   Mixer name : 'Intel CougarPoint HDMI'
   Components : 'HDA:10ec0269,11790628,00100100 HDA:80862805,11790001,00100000'
   Controls : 29
   Simple ctrls : 11
Date: Thu May 9 12:14:51 2013
HibernationDevice: RESUME=UUID=add8fe24-1f1e-4ca7-a2d6-a0f40c03383f
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release i386 (20120423)
MachineType: TOSHIBA TECRA R850
MarkForUpload: True
 PATH=(custom, no user)
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-41-generic-pae root=UUID=ffc754ea-32ed-4ae7-b471-bca82bd54afb ro elevator=deadline quiet splash vt.handoff=7
 linux-restricted-modules-3.2.0-41-generic-pae N/A
 linux-backports-modules-3.2.0-41-generic-pae N/A
 linux-firmware 1.79.4
SourcePackage: linux
StagingDrivers: mei
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 08/25/2011
dmi.bios.vendor: TOSHIBA
dmi.bios.version: Version 3.10
dmi.board.asset.tag: 0000000000
dmi.board.name: Portable PC
dmi.board.vendor: TOSHIBA
dmi.board.version: Version A0
dmi.chassis.asset.tag: 0000000000
dmi.chassis.type: 10
dmi.chassis.vendor: TOSHIBA
dmi.chassis.version: Version 1.0
dmi.modalias: dmi:bvnTOSHIBA:bvrVersion3.10:bd08/25/2011:svnTOSHIBA:pnTECRAR850:pvrPT525E-043021GH:rvnTOSHIBA:rnPortablePC:rvrVersionA0:cvnTOSHIBA:ct10:cvrVersion1.0:
dmi.product.name: TECRA R850
dmi.product.version: PT525E-043021GH
dmi.sys.vendor: TOSHIBA

Jens (jens-launchpad-net) wrote :

This change was made by a bot.

Changed in linux (Ubuntu):
status: New → Confirmed

There is still a bug, even with the "vendor" kernel parameter: The brightness setting does not survive a suspend/resume cycle. This would not matter so much if the brightness after resuming were not fixed to zero (i.e. invisible).

Even worse: with an external monitor attached, first (upon resume) only the external screen is readable, when you press ESCAPE (at the Ubuntu password prompt) the screen blanks, and the system does not suspend again (this is what I would have expected), BUT the screen does not reappear at all upon any keypresses - even the external screen stays blank.

Jens (jens-launchpad-net) wrote :

(The last issue is because after disconnecting and reconnecting the external screen, the password prompt is on the (dark) internal screen and the external screen is empty.)

Jens (jens-launchpad-net) wrote :

After further testing:

With "acpi_backlight=vendor", brightness is adjustable in about 20 steps until the first suspend, the minimum setting switches the display off completely. After resume, the "brightness" file in /sys says "7" (max value) but the screen backlight is off. This is irrespective of an external monitor connected to my notebook.

Without "acpi_backlight=vendor", the brightness is adjustable in 8 steps until the first suspend, the minimum setting sets the screen very dark, but still readable. After resume, "actual_brightness" is 0, "brightness" is 7, the hotkeys show a popup window with an adjustable brightness bar, but the actual brightness of the screen is fixed to the value it had before suspending, and is not changeable any more with the hotkeys.

Joseph Salisbury (jsalisbury) wrote :

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v3.9 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-upstream'.
Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.9-saucy/

Changed in linux (Ubuntu):
importance: Undecided → Medium
status: Confirmed → Incomplete
Jens (jens-launchpad-net) wrote :

kernel-bug-exists-upstream: screen brightness not adjustable any more after suspending and resuming once.

Tried with linux-image-3.9.0-030900-generic-i386.

tags: added: kernel-bug-exists-upstream
Jens (jens-launchpad-net) wrote :

Do you need anything else before removing "incomplete" status from this bug?

Jens (jens-launchpad-net) wrote :

This still exists on the current Ubuntu 12.04.2 kernel (3.5.0-43).

Changed in linux (Ubuntu):
status: Incomplete → Confirmed

Jens, could you please provide the full computer model as noted on the sticker?

description: updated
tags: added: kernel-bug-exists-upstream-v3.9 needs-full-computer-model needs-upstream-testing
removed: backlight kernel-bug-exists-upstream notebook toshiba
Changed in linux (Ubuntu):
status: Confirmed → Incomplete
Jens (jens-launchpad-net) wrote :

Tecra R850-19Z
PART NO. PT525E-043021GH
2520M / 4G / 320G / 15.6HD+ / DS2 / B / W 1I / +0 / 3OSI
SERIAL NO. xxxxxxxxxxxx

Changed in linux (Ubuntu):
status: Incomplete → Confirmed
summary: - Screen brightness not changable via applet or hotkeys in Ubuntu 12.04 on
- Toshiba R850 notebook
+ https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1178205
summary: - https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1178205
+ [Toshiba Tecra R850-19Z] Screen brightness not changable via applet or
+ hotkeys in Ubuntu 12.04
tags: added: bios-outdated-4.10
removed: needs-full-computer-model

Jens, as per http://www.toshiba.co.uk/innovation/download_bios.jsp?service=UK an update is available for your BIOS (4.10). If you update to this, does it change anything?

If not, 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.

Changed in linux (Ubuntu):
status: Confirmed → Incomplete
Jens (jens-launchpad-net) wrote :

Unfortunately, I cannot upgrade the BIOS since this is a corporate laptop (my employer's). I have also reported this issue to them, they are probably reading this bug report's progress too. Also, since the BIOS update doesn't seem to have a list of fixed bugs or issues, I'd be hesitant to perform a "blind update".

Here is the output you requested:
Version 3.10

Changed in linux (Ubuntu):
status: Incomplete → Confirmed
tags: added: cannot-upgrade-bios
Changed in linux (Ubuntu):
status: Confirmed → Incomplete
tags: removed: cannot-upgrade-bios
Launchpad Janitor (janitor) wrote :

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]

Changed in linux (Ubuntu):
status: Incomplete → Expired
Jens (jens-launchpad-net) wrote :

Sorry, this is not yet fixed. I cannot upgrade the bios on my business machine (yet - I will have to wait for the admins to allow me, and I'm currently on paternity leave) and if this fixes the bug i'll report back here.

Changed in linux (Ubuntu):
status: Expired → Confirmed
Changed in linux (Ubuntu):
status: Confirmed → Incomplete
Loop (rbyrnes) wrote :

Issue also occurs in Linux Mint 15 (based on 13.04)

I might be able to install Raring or Saucy in their own partition if required

Loop, if you have a bug in Ubuntu, the Ubuntu Kernel team, Ubuntu Bug Control team, and Ubuntu Bug Squad would like you to please file a new report by executing the following in a terminal while booted into a Ubuntu repository kernel (not a mainline one) via:
ubuntu-bug linux

For more on this, please read the official Ubuntu documentation:
Ubuntu Bug Control and Ubuntu Bug Squad: https://wiki.ubuntu.com/Bugs/BestPractices#X.2BAC8-Reporting.Focus_on_One_Issue
Ubuntu Kernel Team: https://wiki.ubuntu.com/KernelTeam/KernelTeamBugPolicies#Filing_Kernel_Bug_reports
Ubuntu Community: https://help.ubuntu.com/community/ReportingBugs#Bug_reporting_etiquette

When opening up the new report, please feel free to subscribe me to it.

Please note, not filing a new report would delay your problem being addressed as quickly as possible.

No need exists to comment here at this time. After reading the above documentation in it's entirety, if you have further questions or comments, you are welcome to redirect them to the appropriate mailing list or forum via http://www.ubuntu.com/support/community/mailinglists , or you may contact me directly.

Thank you for your understanding.

Launchpad Janitor (janitor) wrote :

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]

Changed in linux (Ubuntu):
status: Incomplete → Expired
Jens (jens-launchpad-net) wrote :

The BIOS update by Toshiba does not report to fix anything display related, so our internal IT does not allow me to update the BIOS. Besides, various Windows versions do not have this problem (there are other display issues on Windows, but a BIOS update is not allowed unless its changelog refers to changes regarding the internal display).

Is there anything else I can do to fix this?

Changed in linux (Ubuntu):
status: Expired → Confirmed
summary: - [Toshiba Tecra R850-19Z] Screen brightness not changable via applet or
- hotkeys in Ubuntu 12.04
+ [Toshiba Tecra R850-19Z PT525E] Screen brightness not changable via
+ applet or hotkeys in Ubuntu 12.04

Jens, OEMs in general do not provide a full, and transparent detail of what a BIOS update would help address. So, if your IT department gave you some limp noodle reason to deny you an update, it is just silly. With regards to the BIOS update for your model, it notes verbatim:
"This Bios Update adds increased functionality to your system."

Vague, and could be interpreted to anything. Hence the reason to update. I would circle back with them, and refer them to a URL of this bug report.

Jens (jens-launchpad-net) wrote :

I'm sorry, but this is not a "limp noodle reason". For any production environment, the golden rule - apart from "never change a running system" - is always to implement changes ONLY if they fix something that is broken.
Our IT department's statement is roughly: if there is a bug, they require a fix that considers specifically this bug fixed in a changelog or release notes. Only then will it be tested internally before being (automatically) deployed to employees' machines. This applies to everything - drivers, BIOS upgrades, application software. If the OEM cannot provide this level of service, and bugs are not being fixed, they will eventually simply lose a (300'000-employee) customer. But maybe you need a corporate support contract to get this level of attention.

I'll try to find out what internal info we have from Toshiba, but since I already know that the Toshiba BIOS upgrade isn't on any internal todo list, I won't hold my breath. Maybe somebody who owns this notebook privately can upgrade his/her BIOS and check.

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