Bug 27762

Summary: Brightness Adjustment on Toshiba nb305 Netbooks is non-functional.
Product: Drivers Reporter: Cody P Schafer (devel)
Component: Video(DRI - Intel)Assignee: drivers_video-dri-intel (drivers_video-dri-intel)
Severity: normal CC: devel, florian, maciej.rutecki, rjw
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: 2.6.38-rc2-00091-gc723fda Tree: Mainline
Regression: Yes
Bug Depends on:    
Bug Blocks: 27352    

Description Cody P Schafer 2011-01-29 03:47:45 UTC
The same as https://bugzilla.kernel.org/show_bug.cgi?id=16405, bug reappeared in the kernel.

What Happens: brightness up and down keys do not change screen brightness, and no items appear under /sys/class/backlight.

Expected: brightness up and down keys adjust brightness of screen up and down (respectively). /sys/class/backlight/*/brightness exsists and allows modification of screen brightness

Why this is not happening:
The call to acpi_video_register is deferred in drivers/acpi/video.c:acpi_video_init() until the intel opregion code in drivers/gpu/drm/intel/intel_opregion.c (previously i915_opregion.c).

In bug 16405 (which is linked at the start of this report), it was determined that the failure to adjust brightness occurred when opregion initialization failed and did not call acpi_video_register.

It appears that the patch 44834a67c0082e2cf74b16be91e49108b1432d65 removed this fallback in rewriting the intel_opregion_{init,fini} functions.
Comment 1 Rafael J. Wysocki 2011-02-03 21:55:50 UTC
First-Bad-Commit : 44834a67c0082e2cf74b16be91e49108b1432d65
Comment 2 Rafael J. Wysocki 2011-02-20 10:46:43 UTC
On Sunday, February 20, 2011, John Mesmon wrote:
> Not sure when this was fixed, but
> a5bbef0b2deb7b943f095181309ecc9e1fc91c0f works.
> On Sat, Feb 12, 2011 at 6:05 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > This message has been generated automatically as a part of a summary report
> > of recent regressions.
> >
> > The following bug entry is on the current list of known regressions
> > from 2.6.37.  Please verify if it still should be listed and let the
> tracking team
> > know (either way).
> >
> >
> > Bug-Entry       : http://bugzilla.kernel.org/show_bug.cgi?id=27762
> > Subject         : Brightness Adjustment on Toshiba nb305 Netbooks is
> non-functional.
> > Submitter       : John Mesmon <jmesmon@gmail.com>
> > Date            : 2011-01-29 03:47 (15 days old)