ubuntu 12.04亮度无法调节和无法保存屏幕亮度解决办法

经过多次更改失败重装后终于在官网的answers找到了解决办法：原文链接 http://askubuntu.com/questions/3841/desktop-doesnt-remember-brightness-settings-after-a-reboot 1、解决reboot后无法保存屏幕亮度：

[cpp] view plaincopysudo gedit /etc/rc.local打开后你会看到如下内容：#!/bin/sh -e## rc.local## This script is executed at the end of each multiuser runlevel.# Make sure that the script will “exit 0″ on success or any other# value on error.## In order to enable or disable this script just change the execution# bits.## By default this script does nothing.#exit 0

[/code]插入这句话到代码中：

echo 0 > /sys/class/backlight/acpi_video0/brightness

保证修改后代码如下，注意exit前的“#”

[cpp] view plaincopy#!/bin/sh -e## rc.local## This script is executed at the end of each multiuser runlevel.# Make sure that the script will “exit 0″ on success or any other# value on error.## In order to enable or disable this script just change the execution# bits.## By default this script does nothing.echo 0 > /sys/class/backlight/acpi_video0/brightnessexit 0[/code]其中echo 后面的值为0-10，对应为0到100%,如echo 5表示一半亮度保存后退出，重启就可以了。注意：大多数人都是acpi_video0，根据自己/sys/class/backlight/下面文件决定2、亮度调节亮度调节依赖与你的bios和内核版本，你可以尝试以下代码：kernel boot选项：

当你启动系统时，出现在grup的屏幕时，按e键进行编辑，在kernel这一行添加：

[cpp]view plaincopynomodeset acpi_backlight=vendor注意：有些硬件可能会是不同的选项.[cpp]view plaincopyIntel - nomodeset acpi_backlight=intel Acer - acpi_backlight=acer_acpi or even acpi_osi=Linux acpi_backlight=legacy.我的电脑是acer 4830tg，我直接写的=vendor也是同样可以正常工作，你也可以通过google去查找你要设置的选项。[cpp]view plaincopyquiet splash nomodeset acpi_backlight=vendor退出启动，如果能正常启动，就把这项选项添加到默认的选项中，编辑文件

/etc/default/grub

[cpp]view plaincopy# command linesudo -e /etc/default/grub# graphicalgksu gedit /etc/default/grub把这一行改成如下：[cpp]view plaincopyGRUB_CMDLINE_LINUX_DEFAULT="quiet splash nomodeset acpi_backlight=vendor"保存，更新grup[cpp]view plaincopysudo update-grub如果还是没有解决问题的话请参照如下链接方法：http://askubuntu.com/questions/3841/desktop-doesnt-remember-brightness-settings-after-a-reboot