Bug 773589 - Screen brightness settings does not have any effect (2011 27inch iMac)
Summary: Screen brightness settings does not have any effect (2011 27inch iMac)
Keywords:
Status: CLOSED NEXTRELEASE
Alias: None
Product: Fedora
Classification: Fedora
Component: kernel
Version: 16
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
Assignee: Kernel Maintainer List
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2012-01-12 10:51 UTC by Andrew Walrond
Modified: 2012-06-01 18:14 UTC (History)
6 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of: 722745
Environment:
Last Closed: 2012-06-01 18:14:07 UTC
Type: ---
Embargoed:


Attachments (Terms of Use)

Description Andrew Walrond 2012-01-12 10:51:23 UTC
+++ This bug was initially created as a clone of Bug #722745 +++

When you adjust the screen brightness, either in gnome or using the brightness
keys on the keyboard, the sliders change but there is no difference on the
actual brightness of the screen

HW: 2011 27 inch iMac, smolt:
http://www.smolts.org/client/show/pub_d9693c43-4ee8-4a8c-82a8-5332c6481f4d

I am using Refit to boot into Fedora.

--- Additional comment from andreas.tunek on 2011-08-05 13:41:12 EDT ---

Still happens in 2.6.40....

Comment 1 Andrew Walrond 2012-01-12 11:03:27 UTC
This was working fine after the initial install of fc16, but stopped working after upgrades.

Writing to /proc/acpi/ doesn't work so I suspect a kernel regression. Infact the relevant acpi files are missing completely now so perhaps the kernel config is missing something?

Comment 2 Andrew Walrond 2012-01-12 11:17:22 UTC
Scratch the last bit; I see it's moved to /sys. Still broken though - this has no effect:

echo 1 > /sys/class/backlight/acpi_video0/brightness

Comment 3 Dave Jones 2012-03-22 17:09:17 UTC
[mass update]
kernel-3.3.0-4.fc16 has been pushed to the Fedora 16 stable repository.
Please retest with this update.

Comment 4 Dave Jones 2012-03-22 17:12:10 UTC
[mass update]
kernel-3.3.0-4.fc16 has been pushed to the Fedora 16 stable repository.
Please retest with this update.

Comment 5 Dave Jones 2012-03-22 17:21:51 UTC
[mass update]
kernel-3.3.0-4.fc16 has been pushed to the Fedora 16 stable repository.
Please retest with this update.

Comment 6 Andrew Walrond 2012-03-23 10:59:35 UTC
Still broken.

Tried gnome settings and manual writing to /sys/class/backlight/acpi_video0/brightness. This value changes but brightness stays at max.

Anything I can do to help test, please shout. It's especially annoying since it worked fine with the initial install of fc16.

Comment 7 Andrew Walrond 2012-03-23 11:16:10 UTC
In fact it's worse than that. My imac now believes it has a battery and keeps hibernating after a few minutes due to critical battery. :(

I'll open a new bug for this.

Comment 8 Andreas Tunek 2012-03-23 20:37:28 UTC
Have you tested booting with the alt-key pressed in? If I do that I can change the brightness.

Comment 9 Andrew Walrond 2012-03-24 10:18:28 UTC
No I haven't tried that. Is this during rEFIt, grub.efi, kernel boot or what? Any ideas why it helps?

Comment 10 Andrew Walrond 2012-06-01 14:29:52 UTC
Fixed in Fedora 17. Yay!


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