Oh, and now I still get the LCD turning off when idle, and what's worse is that
now if I don't do my no_automatic_changes=0 workaround, my brightness keys
don't work at all! What gives?
Also, I'm still curious why the multiples of 13 don't work through /sys/, but
do work through /proc.
** Summary changed:
- LCD backlight turns off between brightness levels during fades, and when on
battery or at idle
+ Brightness keys don't work, and LCD backlight blinks off during fades, and
turns off when dimming on battery or at idle.
** Description changed:
Binary package hint: gnome-power-manager
When gnome-power-manager dims the screen when on battery or when idle, the
backlight turns entirely off.
In addition, during the fade the screen blinks: 100%, OFF, 75%, OFF, 50%, OFF.
cat /proc/acpi/video/VGA/LCD/brightness:
levels: 100 37 12 25 37 50 62 75 87 100
current: 100
The screen is turning off whenever something requests a brightness level
between the available discrete levels; thus the default dim-when-
inactive brightness of 30 turns the backlight off. For a while, I
thought my system was freezing at a black screen at login (battery) or
idle (AC), until I remembered the brightness controls.
One factor in this is the new /sys/class/backlight/ interface for brightness
control, common to all ACPI drivers:
This structure does not seem to provide the same, necessary information, such
as available discrete brightness levels.
/sys/class/backlight/acpi_video0/max_brightness: 100
/sys/class/backlight/acpi_video0/actual_brightness: 62 <== changes
even when keyboard hotkeys are used; g-p-m does not notice this.
/sys/class/backlight/acpi_video0/brightness: 62 <==
changes only when software requests a change.
HAL lists num_levels=101, while ideally it should be 8 or 9. Better yet, the
kernel itself should provide the discrete levels, or rounding issues may appear.
Oddly. the brightness levels 12, 37, 62, and 75 work through echoing into
'brightness', but turn the backlight off if used in g-p-m.
Echoing invalid values there turns the backlight off, but echoing into the
/proc structure returns 'invalid argument'.
Note: the data under /sys/class/backlight is not synchronized with
/proc/acpi/video; for consistency, it should be.
+ EDIT: As of the beginning of October, 2007, my brightness keys don't
+ work at all!
+
(My DSDT also provides sys/class/backlight/acpi_video1/ and
/proc/acpi/video/GFX0/DD0n/ for n from 1 to 5; LCD is 4. However, I
would not expect the values there to be synchronized with acpi_video0
and VGA/LCD.)
** Summary changed:
- Brightness keys don't work, and LCD backlight blinks off during fades, and
turns off when dimming on battery or at idle.
+ LCD backlight turns off when between discrete levels, both from hotkeys and
from dim-on-idle.
** Description changed:
Binary package hint: gnome-power-manager
When gnome-power-manager dims the screen when on battery or when idle, the
backlight turns entirely off.
In addition, during the fade the screen blinks: 100%, OFF, 75%, OFF, 50%, OFF.
cat /proc/acpi/video/VGA/LCD/brightness:
levels: 100 37 12 25 37 50 62 75 87 100
current: 100
The screen is turning off whenever something requests a brightness level
between the available discrete levels; thus the default dim-when-
inactive brightness of 30 turns the backlight off. For a while, I
thought my system was freezing at a black screen at login (battery) or
idle (AC), until I remembered the brightness controls.
One factor in this is the new /sys/class/backlight/ interface for brightness
control, common to all ACPI drivers:
This structure does not seem to provide the same, necessary information, such
as available discrete brightness levels.
/sys/class/backlight/acpi_video0/max_brightness: 100
- /sys/class/backlight/acpi_video0/actual_brightness: 62 <== changes
even when keyboard hotkeys are used; g-p-m does not notice this.
+ /sys/class/backlight/acpi_video0/actual_brightness: 62 <== changes
when software or hotkeys are used.
/sys/class/backlight/acpi_video0/brightness: 62 <==
changes only when software requests a change.
HAL lists num_levels=101, while ideally it should be 8 or 9. Better yet, the
kernel itself should provide the discrete levels, or rounding issues may appear.
- Oddly. the brightness levels 12, 37, 62, and 75 work through echoing into
'brightness', but turn the backlight off if used in g-p-m.
- Echoing invalid values there turns the backlight off, but echoing into the
/proc structure returns 'invalid argument'.
+ Oddly. the brightness levels 12, 37, 62, and 75 work through echoing into
/proc, but turn the backlight off if used in /sys, and thus HAL or g-p-m.
+ Echoing invalid values into /sys turns the backlight off, but echoing into
the /proc structure returns 'invalid argument'.
Note: the data under /sys/class/backlight is not synchronized with
/proc/acpi/video; for consistency, it should be.
-
- EDIT: As of the beginning of October, 2007, my brightness keys don't
- work at all!
(My DSDT also provides sys/class/backlight/acpi_video1/ and
/proc/acpi/video/GFX0/DD0n/ for n from 1 to 5; LCD is 4. However, I
would not expect the values there to be synchronized with acpi_video0
and VGA/LCD.)
+
+ Edit: As of the beginning of October 2003, changes to the kernel 'video'
modue and HAL make me now have to hit my brightness keys 5 times before
reaching the next brightness level; before, the brightness keys were still
managed by the kernel.
+ In addition, upgrading HAL breaks brightness changes until the next boot.
--
LCD backlight turns off when between discrete levels, both from hotkeys and
from dim-on-idle.
https://bugs.launchpad.net/bugs/121833
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