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時間:2015-04-17 17:44:56 作者:qipeng 來源:系統(tǒng)之家 1. 掃描二維碼隨時看資訊 2. 請使用手機瀏覽器訪問: https://m.xitongzhijia.net/xtjc/20150417/45840.html 手機查看 評論 反饋
在Ubuntu系統(tǒng)中,有時會因為屏幕太亮或太暗需要調(diào)節(jié)屏幕亮度, 卻發(fā)現(xiàn)屏幕亮度無法調(diào)整,或調(diào)整后無法保存,遇到這種問題該如何解決呢?
測試環(huán)境:
Acer Aspire 5750G
NVIDIA GeForce GT630M
Ubuntu 12.04 x86_64
其他情況解決方法類似。
調(diào)節(jié)屏幕亮度
Fn不能調(diào)節(jié)屏幕的亮度。因為fn調(diào)節(jié)的是/sys/class/backlight/acpi_video0/brightness文件,而I卡的文件是/sys/class/backlight/intel_backlight/brightness。
一、測試代碼
啟動系統(tǒng),出現(xiàn)grub菜單時,按“e”編輯,在有l(wèi)inux內(nèi)核路徑那一行,添加“acpi_backlight=vendor”,如:
linux /boot/vmlinuz-3.2.0-30-generic root=UUID=75c414be-2e17-407a-b699-94f6a398dff7 ro acpi_backlight=vendor quiet splash
如果能正常啟動,且用fn能調(diào)節(jié)屏幕亮度,說明成功,接著下一步。
二、修改grub
sudo vi /etc/default/grub
找到:
GRUB_CMDLINE_LINUX=“”
改為:
GRUB_CMDLINE_LINUX=“acpi_backlight=vendor“
我的grub文件如下:
# If you change this file, run ‘update-grub’ afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
# info -f grub -n ‘Simple configuration’
GRUB_DEFAULT=0
#GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=3
GRUB_DISTRIBUTOR=`lsb_release -i -s 2》 /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash“
GRUB_CMDLINE_LINUX=”acpi_backlight=vendor“
# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD 。。。)
#GRUB_BADRAM=”0x01234567,0xfefefefe,0x89abcdef,0xefefefef“
# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL=console
# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo‘
#GRUB_GFXMODE=640x480
# Uncomment if you don’t want GRUB to pass ”root=UUID=xxx“ parameter to Linux
#GRUB_DISABLE_LINUX_UUID=true
# Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY=”true“
# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE=”480 440 1“
更新grub.cfg
➜ ~ sudo update-grub
查看grub.cfg 發(fā)現(xiàn)其中每個啟動項都加入了“acpi_backlight=vendor”
➜ ~ vi /boot/grub/grub.cfg
設(shè)定屏幕初始亮度
重啟后發(fā)現(xiàn),屏幕亮度又恢復(fù)為最大亮度。
查看影響屏幕亮度的文件
➜ ~ vi /sys/class/backlight/intel_backlight/brightness
調(diào)節(jié)幾次屏幕亮度發(fā)現(xiàn)其中數(shù)值會改變,我的筆記本數(shù)值范圍為0~976。
手動修改該數(shù)值,會發(fā)現(xiàn)屏幕亮度隨之改變(需要root用戶執(zhí)行):
➜ ~ su
Password:
root@ www.linuxidc.com :/home/congbo# echo 500 》 /sys/class/backlight/intel_backlight/brightness
因此,將該語句添加到 /etc/rc.local 就能開機自動設(shè)定屏幕初始亮度了。
修改/etc/rc.local如下(需要root用戶執(zhí)行):
#!/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 500 》 /sys/class/backlight/intel_backlight/brightness
exit 0
調(diào)節(jié)gamma值
➜ ~ xgamma -gamma .7
-》 Red 1.000, Green 1.000, Blue 1.000
《- Red 0.700, Green 0.700, Blue 0.700
上面就是Ubuntu調(diào)節(jié)及保存屏幕亮度失敗的解決方法了,出現(xiàn)這種問題的時候,先測試代碼,再修改grub即可。
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