http://bugzilla.kernel.org/show_bug.cgi?id=12235
------- Comment #1 from anonym...@kernel-bugs.osdl.org 2008-12-16 10:00 ------- Reply-To: a...@linux-foundation.org (switched to email. Please respond via emailed reply-to-all, not via the bugzilla web interface). On Tue, 16 Dec 2008 03:36:11 -0800 (PST) bugme-dae...@bugzilla.kernel.org wrote: > http://bugzilla.kernel.org/show_bug.cgi?id=12235 > > Summary: /sys/devices/virtual/backlight/acpi_video0/brightness > has it backwards > Product: ACPI > Version: 2.5 > KernelVersion: 2.6.28-rc8 > Platform: All > OS/Version: Linux > Tree: Mainline > Status: NEW > Severity: normal > Priority: P1 > Component: Power-Video > AssignedTo: acpi_power-vi...@kernel-bugs.osdl.org > ReportedBy: khashayar.li...@gmail.com > > > Latest working kernel version: > 2.6.27 > > Earliest failing kernel version: > probably 2.6.28-rc1, but could be later in the release candidates. > > Distribution: > Ubuntu 8.10 > > Hardware Environment: > Asus, N20A, all intel. > > Problem Description: > If the laptop loads the video module at boot time, > /sys/devices/virtual/backlight/acpi_video0/brightness is created. However, > it's > all backwards, confusing applications like gnome-power-manager and the likes > (well, that basically means hal). Echoing 0 to 'brightness' raises the > backlight of this laptop to maximum. Echoing 13 to it, takes the backlight to > a > minimum. > actual_brightness' seems to stay at 0 at all times. > > If I disalllow the video module to be loaded at boot time, there's no > backlight > interface in /sys/class/backlight/*. But, nevertheless, the xbacklight utility > and hal seem to be able to control the backlight just fine. In this latter > case, withouth the video module loaded, xbacklight & hal handle the backlight > correctly, i.e. less means lower backlight, and more means brighter backlight. > > I just confirmed this problem exists with the latest git from Linus' tree, as > well as the rc8 patch. > > If I remember correctly, the 2.6.27-series created an interface under > /sys/devices/platform/asus-laptop/ for controlling backlight which worked just > fine. > > Please let me know what additional information to post. I'd love to have this > fixed before the 2.6.28 release. OK, that's weird. I have a suspicion that we're about to find out that this is intentional, but I don't know what the fix is.. -- Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the assignee for the bug, or are watching the assignee. ------------------------------------------------------------------------------ SF.Net email is Sponsored by MIX09, March 18-20, 2009 in Las Vegas, Nevada. The future of the web can't happen without you. Join us at MIX09 to help pave the way to the Next Web now. Learn more and register at http://ad.doubleclick.net/clk;208669438;13503038;i?http://2009.visitmix.com/ _______________________________________________ acpi-bugzilla mailing list acpi-bugzilla@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/acpi-bugzilla
