Bug 901375 - Kernel 3.7 on FC 18 breaks KDE backlight control
Summary: Kernel 3.7 on FC 18 breaks KDE backlight control
Keywords:
Status: CLOSED WONTFIX
Alias: None
Product: Fedora
Classification: Fedora
Component: kernel
Version: 18
Hardware: x86_64
OS: Linux
unspecified
medium
Target Milestone: ---
Assignee: Kernel Maintainer List
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2013-01-18 04:44 UTC by jfceklosky
Modified: 2020-02-11 02:17 UTC (History)
12 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2014-02-05 15:07:34 UTC
Type: Bug
Embargoed:
jfceklosky: needinfo-


Attachments (Terms of Use)

Description jfceklosky 2013-01-18 04:44:53 UTC
Description of problem:
Fedora 18 with the 3.6.10 based kernel worked perfectly with the brightness using the KDE power applet.

Once FC 18 was updated to 3.7.2.-201.fc18 the above fails to work.  The brightness is stuck at 90%


Version-Release number of selected component (if applicable):


How reproducible:

All the time

Steps to Reproduce:
1. Boot with 3.6.10 see the keys work
2. Boot with 3.7.2 see the keys don't work
3.
  
Actual results:

No brightness changes

Expected results:

KDE power application should adjust brightness

Additional info:

Asus K55A laptop

xbacklight does work with when using the 3.7.2 kernel, but the KDE power app does not.

The asus modules are loaded and asus_wmi reports that the Backlight is controlled by ACPI.

In /sys/class/backlight there is acpi_video0 and intel_backlight.

With the 3.6 kernel booted the acpi *brightness values report values from 1 to 10

With the 3.7 kernel booted the acpi *brightness values report values from 0 to 100.

The intel_back *brightness reports values from 0 to 4882.

I can provide any other required details.

Comment 1 praxone 2013-01-21 04:51:31 UTC
same with gnome-shell and cinnamon
Issue is unresolved in todays update also( 3.7.2-204 fc18 kernel)
Laptop is HP dv7t 7000
Booted in UEFI

Comment 2 jfceklosky 2013-01-21 05:01:30 UTC
(In reply to comment #1)
> same with gnome-shell and cinnamon
> Issue is unresolved in todays update also( 3.7.2-204 fc18 kernel)
> Laptop is HP dv7t 7000
> Booted in UEFI

Yes the updated kernel still does not work on the K55A.

I think the graphic tools to update the brightness are busted.  They appear to be using the acpi video control, which is NOT working with the FC 3.7 kernels.

You can manually change the brightness by updating
/sys/class/backup/acpi_video0/brightness directly

Comment 3 praxone 2013-01-21 05:20:27 UTC
gnome works but,
always boots into 0 backlight(dimmest) and keypress take 100 instead of 10 as max value as 10% progress in backlight is actually 100%.

Comment 4 jfceklosky 2013-01-21 05:31:23 UTC
(In reply to comment #3)
> gnome works but,
> always boots into 0 backlight(dimmest) and keypress take 100 instead of 10
> as max value as 10% progress in backlight is actually 100%.

The 3.7 kernels are reporting more than 10 levels. Boot with 3.6 and you will see that.  I was added code into the apci/video.c and saw that.

Comment 5 Antoine Cotten 2013-01-23 00:48:42 UTC
(Lenovo ThinkPad X230)
It's actually a general issue, not only related to KDE.
I can reproduce this bug on Gnome 3.6 as well since kernel update 3.6.11 > 3.7.2.
I saw it mentioned on the Arch Linux forum too.

Changing the brightness works by "echo-ing" a value to these files:
/sys/class/backlight/intel_backlight/brightness
-or-
/sys/class/backlight/acpi_video0/brightness

On Gnome the brightness cursor in System Settings works as well.

However the hardware buttons are broken, it just shows a fixed OSD cursor and the values do not change in the previously mentioned files.

I managed to work around the issue by using the following kernel parameter in GRUB: acpi_backlight=vendor. I shows a wrong OSD cursor but changes the brightness correctly.

Comment 6 Antoine Cotten 2013-03-05 16:03:57 UTC
Still happens on the current kernel version: 3.8.1-201.fc18.x86_64

Comment 7 Johan Swensson 2013-10-29 21:11:56 UTC
This component refers to the userspace application named acpi and not the kernel provided acpi interface.

Changing to kernel.

Comment 8 Josh Boyer 2013-10-29 23:32:12 UTC
is this still happening with 3.11.4 or newer?

Comment 9 Fedora End Of Life 2013-12-21 10:30:11 UTC
This message is a reminder that Fedora 18 is nearing its end of life.
Approximately 4 (four) weeks from now Fedora will stop maintaining
and issuing updates for Fedora 18. It is Fedora's policy to close all
bug reports from releases that are no longer maintained. At that time
this bug will be closed as WONTFIX if it remains open with a Fedora 
'version' of '18'.

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version' 
to a later Fedora version prior to Fedora 18's end of life.

Thank you for reporting this issue and we are sorry that we may not be 
able to fix it before Fedora 18 is end of life. If you would still like 
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version prior to Fedora 18's end of life.

Although we aim to fix as many bugs as possible during every release's 
lifetime, sometimes those efforts are overtaken by events. Often a 
more recent Fedora release includes newer upstream software that fixes 
bugs or makes them obsolete.

Comment 10 Fedora End Of Life 2014-02-05 15:07:40 UTC
Fedora 18 changed to end-of-life (EOL) status on 2014-01-14. Fedora 18 is
no longer maintained, which means that it will not receive any further
security or bug fix updates. As a result we are closing this bug.

If you can reproduce this bug against a currently maintained version of
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