(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-daemon@xxxxxxxxxxxxxxxxxxx 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-video@xxxxxxxxxxxxxxxxxxxx > ReportedBy: khashayar.lists@xxxxxxxxx > > > 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.. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
