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.
First-Bad-Commit : 44834a67c0082e2cf74b16be91e49108b1432d65
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)