将 Ubuntu 11.10 升级到 12.04 后，我无法控制 Toshiba Satellite L650 的亮度。在 Ubuntu 11.10 下一切正常。
现在我只能在终端中使用以下命令更改亮度：
echo 3 > /sys/class/backlight/acpi_video0/brightness
我还有一个名为 /sys/class/backlight/toshiba/ 的文件夹，其中有文件亮度
当我在文件中使用键盘快捷键 Fn-F6 和 Fn-F7 值时亮度（来自东芝文件夹）发生了变化，但计算机中的亮度没有变化，因为它似乎是由 /acpi_video0/ 文件夹中的值控制的。
我尝试从这里更改 grub 中的配置：
GRUB_CMDLINE_LINUX=""
更改为：
GRUB_CMDLINE_LINUX="acpi_backlight=vendor"
但是文件夹 /toshiba/ 消失了，我即使在终端中也无法改变亮度。
acpi 已安装。
有人能帮我找到解决办法吗？
lspci给出以下输出：
00:00.0 Host bridge: Intel Corporation Core Processor DRAM Controller (rev 02)
00:01.0 PCI bridge: Intel Corporation Core Processor PCI Express x16 Root Port (rev 02)
00:16.0 Communication controller: Intel Corporation 5 Series/3400 Series Chipset HECI Controller (rev 06)
00:1a.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 05)
00:1b.0 Audio device: Intel Corporation 5 Series/3400 Series Chipset High Definition Audio (rev 05)
00:1c.0 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 1 (rev 05)
00:1c.1 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 2 (rev 05)
00:1c.4 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 5 (rev 05)
00:1d.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 05)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev a5)
00:1f.0 ISA bridge: Intel Corporation Mobile 5 Series Chipset LPC Interface Controller (rev 05)
00:1f.2 SATA controller: Intel Corporation 5 Series/3400 Series Chipset 4 port SATA AHCI Controller (rev 05)
00:1f.3 SMBus: Intel Corporation 5 Series/3400 Series Chipset SMBus Controller (rev 05)
00:1f.6 Signal processing controller: Intel Corporation 5 Series/3400 Series Chipset Thermal Subsystem (rev 05)
01:00.0 VGA compatible controller: Advanced Micro Devices [AMD] nee ATI Madison [Radeon HD 5000M Series]
01:00.1 Audio device: Advanced Micro Devices [AMD] nee ATI Redwood HDMI Audio [Radeon HD 5000 Series]
02:00.0 Ethernet controller: Atheros Communications Inc. AR8152 v1.1 Fast Ethernet (rev c1)
03:00.0 Network controller: Broadcom Corporation BCM4313 802.11b/g/n Wireless LAN Controller (rev 01)
3f:00.0 Host bridge: Intel Corporation Core Processor QuickPath Architecture Generic Non-core Registers (rev 02)
3f:00.1 Host bridge: Intel Corporation Core Processor QuickPath Architecture System Address Decoder (rev 02)
3f:02.0 Host bridge: Intel Corporation Core Processor QPI Link 0 (rev 02)
3f:02.1 Host bridge: Intel Corporation Core Processor QPI Physical 0 (rev 02)
3f:02.2 Host bridge: Intel Corporation Core Processor Reserved (rev 02)
3f:02.3 Host bridge: Intel Corporation Core Processor Reserved (rev 02)
答案1
这是 OP 在问题：
我刚刚找到解决方案并且亮度开始起作用。
我只是改了一下：
gedit /etc/X11/xorg.conf
我的 xorg.conf 非常短：
Section "Screen"
Identifier "Default Screen"
DefaultDepth 24
EndSection
Section "Module"
Load "glx"
EndSection
所以最后补充道：
Section "Device"
Identifier "ATI Radeon HD 5000M"
Driver "radeon"
Option "NoLogo" "True"
Option "RegistryDwords" "EnableBrightnessControl=1"
EndSection
现在可以了。