Bug 550895

Summary:	Cannot adjust backlight brightness on Sony Vaio FW290
Product:	[Fedora] Fedora	Reporter:	Sean Carlos <sean.carlos>
Component:	kernel	Assignee:	Kernel Maintainer List <kernel-maint>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	low
Version:	12	CC:	anton, dougsland, gansalmon, itamar, jskala, kernel-maint
Target Milestone:	---
Target Release:	---
Hardware:	x86_64
OS:	Linux
URL:	http://vaioubuntu.wordpress.com/2008/12/04/finally-a-brightness-how-to-for-vaio-fw-series/
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2010-03-08 07:46:35 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Sean Carlos 2009-12-28 01:14:11 UTC

Description of problem:

It is impossible to dim backlight UNLESS a patched DSDT is loaded at boot time.  Then all is well.  

The full details, including work-around, were documented by an Ubuntu user here

http://vaioubuntu.wordpress.com/2008/12/04/finally-a-brightness-how-to-for-vaio-fw-series/

For Fedora, I use the tuxonice kernel to load the patched DSDT.

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

All - has never worked out of the box in Fedora.

How reproducible:

Steps to Reproduce:
1.  Try to dim backlight using either keys or gnome control.
  
Actual results:

Nothing happens (unless using patched DSDT)

Expected results:

Backlight should be adjustable.

Additional info:

The backlight dimmer works out of the box using the latest (9.10) Ubuntu release - I tried it using their live CD.  So there should be a viable solution.

Hardware: Sony Vaio VGN-FW290 (and apparently others)
Video: ATI Technologies Inc Mobility Radeon HD 3650

I don't really know if this is an ACPI problem or a Kernel problem.

Comment 1 Sean Carlos 2009-12-29 13:06:07 UTC

Changed component to kernel based on note in bug report 549074

Comment 2 Sean Carlos 2010-03-08 07:46:35 UTC

I'm seeing this issue fixed with the current kernel 2.6.32.9-67.fc12.x86_64 - very nice.