在ubuntu 11.10 / 12.04 的螢幕 光陰 問題

首先 牽涉 到 兩種問題

  Desktop doesn't remember brightness settings after a reboot

 Decrease Backlight Below Minimum

根據 我的電腦 的 顯示器驅動是 INTEL HD 3000 圖形顯示卡

可參巧以下 的其中回覆

This function, the backlight control, is dependent on your bios and kernel version.

Try these four things.

Kernel (boot) options

If that works, edit /etc/default/grub and add those options to the default options.

# command line
sudo -e /etc/default/grub

# graphical
gksu gedit /etc/default/grub

Edit the "GRUB_CMDLINE_LINUX_DEFAULT" line so it looks like this

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux acpi_backlight=vendor"

Save your edit, update grub

sudo update-grub

sudo update-initramfs -u -k all

sudo reboot

Command line

If that does not work, you can try to manually set the brightness.

Note: Path may vary with hardware / kernel version, you may need to browse the /proc/acpi directory to find the brightness setting and adjust the following commands accordingly.

IN MY CASE:

sudo nano /sys/class/backlight/ (acpi_video0 / intel_backlight ) /brightness

1. Change the value in this file to 500.
2. Press Ctrl + X to exit.
3. Press Y and Enter to save the file.

This works for me. You can also try echo value > /sys/.../brightness but I get a permission denied message even with sudo.

If that works, add it to /etc/rc.local

# command line
sudo -e /etc/rc.local

# graphical
gksu gedit /etc/rc.local

Add in your setting above "exit 0"

echo VALUE >/sys/class/backlight/(acpi_video0 / intel_backlight )/brightness

xbacklight

You can also try xbacklight

sudo apt-get install xbacklight

You then adjust with the command line

# For 80 % brightness
xbacklight -set 80

Again, add that to /etc/rc.local

# command line
sudo -e /etc/rc.local

# graphical
gksu gedit /etc/rc.local

Add in, above "exit 0"

xbacklight -set 80

setpci

You can try to set your brightness with setpci

You identify your pci bus address with

sudo lspci | grep VGA

Example

00:02.0 VGA compatible controller: Cirrus Logic GD 5446

setpci -s 00:02.0 F4.B=80

If you get your setting wrong, most likely you will just loose your display, and have to reboot. As this is a hardware setting, you really need to identify your hardware and research the settings first.

Other resources

Intel - https://bbs.archlinux.org/viewtopic.php?id=74914

Ubuntu man page setpci

update-initramfs - generate an initramfs image