Bug 1005409 - acpi brightness weirdness
Summary: acpi brightness weirdness
Alias: None
Product: Fedora
Classification: Fedora
Component: kernel
Version: rawhide
Hardware: Unspecified
OS: Unspecified
Target Milestone: ---
Assignee: Kernel Maintainer List
QA Contact: Fedora Extras Quality Assurance
Depends On:
TreeView+ depends on / blocked
Reported: 2013-09-06 20:23 UTC by Kevin Fenzi
Modified: 2013-09-15 18:42 UTC (History)
6 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2013-09-15 18:42:26 UTC
Type: Bug

Attachments (Terms of Use)

Description Kevin Fenzi 2013-09-06 20:23:05 UTC

Close lid and go away for a while. I have xfce4-power-manager set to switch off the display if the computer is inactive for 15min.

Come back and open the lid and the brightness is way way down and the controls don't work to change it. 

Xorg.0.log has: 

[ 20260.867] (EE) intel(0): failed to open /sys/class/backlight/acpi_video0/brightness for backlight control: No such file or directory
[ 20260.871] (EE) intel(0): failed to open /sys/class/backlight/acpi_video0/actual_brightness for backlight control: No such file or director

The /sys/class/backlight/acpi_video0 directory doesn't exist. 

However, there is a /sys/class/backlight/acpi_video1 directory. 

Doing a echo 12 > /sys/class/backlight/acpi_video1/brightness causes the lcd to go back to bright. 

So, something is removing the acpi_video0 dir/controls on monitor power off and readding them as 1 after turning back on. 

Happy to provide more info or try things.

Comment 1 Kevin Fenzi 2013-09-15 18:42:26 UTC
This seems to be fixed in 3.12.0-0.rc0.git25.1.fc21.x86_64 at least.

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