I've got stock kernel 2.6.32.3 and Debian (not Ubuntu), so all this FWIW. On my 5810TZ, xrandr --prop does not show BACKLIGHT_CONTROL. Backlight keys do not work, but when booting *without* nomodeset (some posts on the Internets suggest that "nomodeset acpi_backlight=vendor" fixes this, but for me it doesn't), it does show "Backlight" and "BACKLIGHT" (if booting *with* acpi_backlight=vendor, even these settings disappear):
------------------------------------------------------------ $ xrandr --prop Screen 0: minimum 320 x 200, current 1366 x 768, maximum 8192 x 8192 VGA1 disconnected (normal left inverted right x axis y axis) LVDS1 connected 1366x768+0+0 (normal left inverted right x axis y axis) 345mm x 194mm EDID: 00ffffffffffff0030e4020200000000 00130103802313780a28659759548e27 1e505400000001010101010101010101 010101010101561d56c6500020303020 350059c2100000190000000000000000 00000000000000000000000000fe004c 4720446973706c61790a2020000000fc 004c503135365748332d544c41310039 BACKLIGHT: 3 (0x00000003) range: (0,9) Backlight: 3 (0x00000003) range: (0,9) scaling mode: Full supported: None Full Center Full aspect 1366x768 60.0*+ 1360x768 59.8 1024x768 60.0 800x600 60.3 640x480 59.9 HDMI1 disconnected (normal left inverted right x axis y axis) DP1 disconnected (normal left inverted right x axis y axis) DP2 disconnected (normal left inverted right x axis y axis) ------------------------------------------------------------ Doing "xrandr --output LVDS1 --set Backlight 5" (or whatever number from 0..9) doesn't seem to change anything, but I noticed by accident that after setting the value using that command, pressing the backlight setting keys on the keyboard (Fn+arrow keys) sets then the backlight to the brightness set with xrandr. The same actually can be done via /proc: ------------------------------------------------------------ r...@lap:/proc/acpi/video/OVGA# ls -l total 0 dr-xr-xr-x 2 root root 0 Jan 14 01:58 DD01 dr-xr-xr-x 2 root root 0 Jan 14 01:58 DD02 dr-xr-xr-x 2 root root 0 Jan 14 01:58 DD03 dr-xr-xr-x 2 root root 0 Jan 14 01:58 DD04 dr-xr-xr-x 2 root root 0 Jan 14 01:58 DD05 -rw-r--r-- 1 root root 0 Jan 14 01:58 DOS -r--r--r-- 1 root root 0 Jan 14 01:58 info -rw-r--r-- 1 root root 0 Jan 14 01:58 POST -r--r--r-- 1 root root 0 Jan 14 01:58 POST_info -r--r--r-- 1 root root 0 Jan 14 01:58 ROM r...@lap:/proc/acpi/video/OVGA# ls DD0*/brightness DD01/brightness DD02/brightness DD03/brightness DD04/brightness DD05/brightness r...@lap:/proc/acpi/video/OVGA# cat DD*/brightness <not supported> levels: 10 20 30 40 50 60 70 80 90 100 current: 10 <not supported> <not supported> <not supported> r...@lap:/proc/acpi/video/OVGA# echo 50 >DD02/brightness ------------------------------------------------------------ [and now pressing Fn+brightness key immediately sets the display brightness to 50.] /proc/acpi/video/DD02/brightness always reflects the brightness as set by xrandr, but it only seems to take effect when pressing the brightness adjustment keys on the keyboard (which have no effect other than that, although they do send XF86MonBrightnessUp/Down keycodes as shown by xev). -- [Karmic] Brightness Buttson OSD Test Acer Aspire 5810-4657 https://bugs.launchpad.net/bugs/432835 You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is a bug assignee. -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs